"File not found" error in Office Web Apps

Hi,

i have set up in my single server farm the Office Web Apps as descripted in the following article:

Deploy Office Web Apps (Installed on SharePoint 2010 Products)

When i create now a new SiteCollection based on the Blank Template and create a document library with some word documents, i get the following errors:

1.) Clicking on the menuitem View in Browser throws

File not found

2.)When i click on the file name in the library i get:

Word Web App cannot open this document for viewing because of an unexpected error.  To view this document open it in Microsoft Word.

In the ULS i get the following:

09/18/2014 13:04:12.93 w3wp.exe (0x1C78)                      0x0410 SharePoint Foundation         Logging Correlation Data      xmnvMedium  Site=/bog/OWATESTd9db5130-d9d3-4f25-8d4c-8c94eab159c7
09/18/2014 13:04:12.93 w3wp.exe (0x1C78)                      0x0410 Office Web Apps               Office Viewing Architecture   vjyuMedium  Librarian.BeginGetItem(F888fc880ee524f61beba804e78821176m648dc133acbb4432bb233029053d0d01m7d0789a965f243b886e75813fc8510f0m, Silverlight, docdata.xml)d9db5130-d9d3-4f25-8d4c-8c94eab159c7
09/18/2014 13:04:12.93 w3wp.exe (0x1C78)                      0x0410 Office Web Apps               Office Viewing Architecture   vkawMedium  ViewStore.SetCompleted(F888fc880ee524f61beba804e78821176m648dc133acbb4432bb233029053d0d01m7d0789a965f243b886e75813fc8510f0m, Silverlight, docdata.xml) - status = ConversionErrord9db5130-d9d3-4f25-8d4c-8c94eab159c7
09/18/2014 13:04:12.93 w3wp.exe (0x1C78)                      0x0410 Office Web Apps               Office Viewing Architecture   vjzoMedium  Librarian.SetCompleted(F888fc880ee524f61beba804e78821176m648dc133acbb4432bb233029053d0d01m7d0789a965f243b886e75813fc8510f0m, Silverlight, docdata.xml) - status = ConversionErrord9db5130-d9d3-4f25-8d4c-8c94eab159c7
09/18/2014 13:04:12.93 w3wp.exe (0x1C78)                      0x0410 SharePoint Foundation         Monitoring                    b4lyMedium  Leaving Monitored Scope (Request (GET:http://sharepoint2010:80/bog/OWATEST/_vti_bin/docdatahandler.ashx?d=F888fc880ee524f61beba804e78821176m648dc133acbb4432bb233029053d0d01m7d0789a965f243b886e75813fc8510f0m&z=7D0789A9-65F2-43B8-86E7-5813FC8510F01&type=sl&ui=de-DE)). Execution Time=19,0333547978863d9db5130-d9d3-4f25-8d4c-8c94eab159c7
09/18/2014 13:04:12.94 w3wp.exe (0x068C)                      0x1050 Office Web Apps               Office Viewing Architecture   b10eMedium  Created desk"Apple-tab-span" style="white-space:pre;">  
09/18/2014 13:04:12.94 w3wp.exe (0x068C)                      0x1050 Office Web Apps               Office Viewing Architecture   2brtMedium  AppWorker:9c3ee281-ef97-41d3-ada6-90bfa7c160fc worker process is started Exe: AppServerHost.exe Args: /id 9c3ee281-ef97-41d3-ada6-90bfa7c160fc /convertingService net.pipe://127.0.0.1/a57fa3f9-b3f7-4b45-9860-8fdd6ebcc62d /assembly wacword.dll /type WACWS /IsBatchedTracing True /LogQuota 100 WorkerType: WorkerType1 Directory: c:\windows\system32\inetsrv, pid : 13328, IsSandBoxed: True, UniqueSandBoxSid: S-1-5-26473-19571-45394-1377 
09/18/2014 13:04:12.94 w3wp.exe (0x068C)                      0x1050 Office Web Apps               Office Viewing Architecture   viozMedium  RemoveWorker isRemoved: True session id : uuid:f8655b88-00a7-40ec-bdf5-457f5fb9f2df;id=1376, Guid: 4390f3b2-c580-4379-bbd5-b8b90df5e9fc 
09/18/2014 13:04:12.94 w3wp.exe (0x068C)                      0x2150 Office Web Apps               Office Viewing Architecture   4sigMedium  ChildProcess AppServerHost.exe is launched inside worker 9c3ee281-ef97-41d3-ada6-90bfa7c160fc. Pid 13328 
09/18/2014 13:04:12.95 w3wp.exe (0x068C)                      0x2150 Office Web Apps               Office Viewing Architecture   d9hnMedium  NotifyNewChildProcessInWorker has seen AppServerHost.exe in worker 9c3ee281-ef97-41d3-ada6-90bfa7c160fc 
09/18/2014 13:04:13.17 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   viouMedium  ... registering worker 9c3ee281-ef97-41d3-ada6-90bfa7c160fc 
09/18/2014 13:04:13.19 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   vioxMedium  Worker 9c3ee281-ef97-41d3-ada6-90bfa7c160fc is now initialized. 
09/18/2014 13:04:13.20 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   wyqtMonitorableTask thread crashed System.InvalidOperationException: Calling Post() on 'Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext' resulted in multiple callbacks.  This indicates a problem in 'Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext'.     at System.ServiceModel.Dispatcher.ThreadBehavior.SynchronizationContextCallback(Object state)     at Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext.RunTask()    at Microsoft.Office.Web.Common.TaskThread.Run()9c3ee281-ef97-41d3-ada6-90bfa7c160fc
09/18/2014 13:04:13.31 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   vipxMonitorableAppWorker:9c3ee281-ef97-41d3-ada6-90bfa7c160fc application server host exited unexpectedly  (thread: 187) 
09/18/2014 13:04:13.31 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   c78jUnexpectedAppWorker:9c3ee281-ef97-41d3-ada6-90bfa7c160fc ProcessRequestDone() received error response WorkerCrashed, restarting the worker 
09/18/2014 13:04:13.31 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   xpreMedium  Removing worker 9c3ee281-ef97-41d3-ada6-90bfa7c160fc, thread: 187 
09/18/2014 13:04:13.31 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   f2ygMedium  CreateSandBoxedProcessWorker() is called 
09/18/2014 13:04:13.32 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   b10eMedium  Created desk"Apple-tab-span" style="white-space:pre;">  
09/18/2014 13:04:13.33 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   2brtMedium  AppWorker:756afa45-8681-4aa2-8288-5b87b433a239 worker process is started Exe: AppServerHost.exe Args: /id 756afa45-8681-4aa2-8288-5b87b433a239 /convertingService net.pipe://127.0.0.1/a57fa3f9-b3f7-4b45-9860-8fdd6ebcc62d /assembly wacword.dll /type WACWS /IsBatchedTracing True /LogQuota 100 WorkerType: WorkerType1 Directory: c:\windows\system32\inetsrv, pid : 13408, IsSandBoxed: True, UniqueSandBoxSid: S-1-5-26473-19571-45394-1378 
09/18/2014 13:04:13.33 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   viozMedium  RemoveWorker isRemoved: True session id : uuid:f8655b88-00a7-40ec-bdf5-457f5fb9f2df;id=1377, Guid: 9c3ee281-ef97-41d3-ada6-90bfa7c160fc 
09/18/2014 13:04:13.33 w3wp.exe (0x068C)                      0x2150 Office Web Apps               Office Viewing Architecture   4sigMedium  ChildProcess AppServerHost.exe is launched inside worker 756afa45-8681-4aa2-8288-5b87b433a239. Pid 13408 
09/18/2014 13:04:13.33 w3wp.exe (0x068C)                      0x2150 Office Web Apps               Office Viewing Architecture   d9hnMedium  NotifyNewChildProcessInWorker has seen AppServerHost.exe in worker 756afa45-8681-4aa2-8288-5b87b433a239 
09/18/2014 13:04:13.54 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   viouMedium  ... registering worker 756afa45-8681-4aa2-8288-5b87b433a239 
09/18/2014 13:04:13.57 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   vioxMedium  Worker 756afa45-8681-4aa2-8288-5b87b433a239 is now initialized. 
09/18/2014 13:04:13.57 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   wyqtMonitorableTask thread crashed System.InvalidOperationException: Calling Post() on 'Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext' resulted in multiple callbacks.  This indicates a problem in 'Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext'.     at System.ServiceModel.Dispatcher.ThreadBehavior.SynchronizationContextCallback(Object state)     at Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext.RunTask()    at Microsoft.Office.Web.Common.TaskThread.Run()756afa45-8681-4aa2-8288-5b87b433a239
09/18/2014 13:04:13.68 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   vipxMonitorableAppWorker:756afa45-8681-4aa2-8288-5b87b433a239 application server host exited unexpectedly  (thread: 187) 
09/18/2014 13:04:13.68 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   c78jUnexpectedAppWorker:756afa45-8681-4aa2-8288-5b87b433a239 ProcessRequestDone() received error response WorkerCrashed, restarting the worker 
09/18/2014 13:04:13.69 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   xpreMedium  Removing worker 756afa45-8681-4aa2-8288-5b87b433a239, thread: 187 
09/18/2014 13:04:13.69 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   f2ygMedium  CreateSandBoxedProcessWorker() is called 
09/18/2014 13:04:13.70 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   b10eMedium  Created desk"Apple-tab-span" style="white-space:pre;">  
09/18/2014 13:04:13.70 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   2brtMedium  AppWorker:543a7cd7-90f8-4b94-b3e0-4abe0ec50b49 worker process is started Exe: AppServerHost.exe Args: /id 543a7cd7-90f8-4b94-b3e0-4abe0ec50b49 /convertingService net.pipe://127.0.0.1/a57fa3f9-b3f7-4b45-9860-8fdd6ebcc62d /assembly wacword.dll /type WACWS /IsBatchedTracing True /LogQuota 100 WorkerType: WorkerType1 Directory: c:\windows\system32\inetsrv, pid : 13488, IsSandBoxed: True, UniqueSandBoxSid: S-1-5-26473-19571-45394-1379 
09/18/2014 13:04:13.70 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   viozMedium  RemoveWorker isRemoved: True session id : uuid:f8655b88-00a7-40ec-bdf5-457f5fb9f2df;id=1378, Guid: 756afa45-8681-4aa2-8288-5b87b433a239 
09/18/2014 13:04:13.70 w3wp.exe (0x068C)                      0x2150 Office Web Apps               Office Viewing Architecture   4sigMedium  ChildProcess AppServerHost.exe is launched inside worker 543a7cd7-90f8-4b94-b3e0-4abe0ec50b49. Pid 13488 
09/18/2014 13:04:13.70 w3wp.exe (0x068C)                      0x2150 Office Web Apps               Office Viewing Architecture   d9hnMedium  NotifyNewChildProcessInWorker has seen AppServerHost.exe in worker 543a7cd7-90f8-4b94-b3e0-4abe0ec50b49 
09/18/2014 13:04:13.91 w3wp.exe (0x068C)                      0x1050 Office Web Apps               Office Viewing Architecture   viouMedium  ... registering worker 543a7cd7-90f8-4b94-b3e0-4abe0ec50b49 
09/18/2014 13:04:13.92 w3wp.exe (0x068C)                      0x1050 Office Web Apps               Office Viewing Architecture   vioxMedium  Worker 543a7cd7-90f8-4b94-b3e0-4abe0ec50b49 is now initialized. 
09/18/2014 13:04:13.93 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   wyqtMonitorableTask thread crashed System.InvalidOperationException: Calling Post() on 'Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext' resulted in multiple callbacks.  This indicates a problem in 'Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext'.     at System.ServiceModel.Dispatcher.ThreadBehavior.SynchronizationContextCallback(Object state)     at Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext.RunTask()    at Microsoft.Office.Web.Common.TaskThread.Run()543a7cd7-90f8-4b94-b3e0-4abe0ec50b49
09/18/2014 13:04:14.04 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   vipxMonitorableAppWorker:543a7cd7-90f8-4b94-b3e0-4abe0ec50b49 application server host exited unexpectedly  (thread: 187) 
09/18/2014 13:04:14.04 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   c78jUnexpectedAppWorker:543a7cd7-90f8-4b94-b3e0-4abe0ec50b49 ProcessRequestDone() received error response WorkerCrashed, restarting the worker 
09/18/2014 13:04:14.04 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   xpreMedium  Removing worker 543a7cd7-90f8-4b94-b3e0-4abe0ec50b49, thread: 187 
09/18/2014 13:04:14.04 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   f2ygMedium  CreateSandBoxedProcessWorker() is called 
09/18/2014 13:04:14.05 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   b10eMedium  Created desk"Apple-tab-span" style="white-space:pre;">  
09/18/2014 13:04:14.06 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   2brtMedium  AppWorker:6e96c591-38f8-4691-897d-588cb92206d1 worker process is started Exe: AppServerHost.exe Args: /id 6e96c591-38f8-4691-897d-588cb92206d1 /convertingService net.pipe://127.0.0.1/a57fa3f9-b3f7-4b45-9860-8fdd6ebcc62d /assembly wacword.dll /type WACWS /IsBatchedTracing True /LogQuota 100 WorkerType: WorkerType1 Directory: c:\windows\system32\inetsrv, pid : 13564, IsSandBoxed: True, UniqueSandBoxSid: S-1-5-26473-19571-45394-1380 
09/18/2014 13:04:14.06 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   viozMedium  RemoveWorker isRemoved: True session id : uuid:f8655b88-00a7-40ec-bdf5-457f5fb9f2df;id=1379, Guid: 543a7cd7-90f8-4b94-b3e0-4abe0ec50b49 
09/18/2014 13:04:14.06 w3wp.exe (0x068C)                      0x2150 Office Web Apps               Office Viewing Architecture   4sigMedium  ChildProcess AppServerHost.exe is launched inside worker 6e96c591-38f8-4691-897d-588cb92206d1. Pid 13564 
09/18/2014 13:04:14.06 w3wp.exe (0x068C)                      0x2150 Office Web Apps               Office Viewing Architecture   d9hnMedium  NotifyNewChildProcessInWorker has seen AppServerHost.exe in worker 6e96c591-38f8-4691-897d-588cb92206d1 
09/18/2014 13:04:14.25 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   viouMedium  ... registering worker 6e96c591-38f8-4691-897d-588cb92206d1 
09/18/2014 13:04:14.27 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   vioxMedium  Worker 6e96c591-38f8-4691-897d-588cb92206d1 is now initialized. 
09/18/2014 13:04:14.28 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   wyqtMonitorableTask thread crashed System.InvalidOperationException: Calling Post() on 'Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext' resulted in multiple callbacks.  This indicates a problem in 'Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext'.     at System.ServiceModel.Dispatcher.ThreadBehavior.SynchronizationContextCallback(Object state)     at Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext.RunTask()    at Microsoft.Office.Web.Common.TaskThread.Run()6e96c591-38f8-4691-897d-588cb92206d1
09/18/2014 13:04:14.38 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   vipxMonitorableAppWorker:6e96c591-38f8-4691-897d-588cb92206d1 application server host exited unexpectedly  (thread: 187) 
09/18/2014 13:04:14.38 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   c78jUnexpectedAppWorker:6e96c591-38f8-4691-897d-588cb92206d1 ProcessRequestDone() received error response WorkerCrashed, restarting the worker 
09/18/2014 13:04:14.38 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   xpreMedium  Removing worker 6e96c591-38f8-4691-897d-588cb92206d1, thread: 187 
09/18/2014 13:04:14.38 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   f2ygMedium  CreateSandBoxedProcessWorker() is called 
09/18/2014 13:04:14.40 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   b10eMedium  Created desk"Apple-tab-span" style="white-space:pre;">  
09/18/2014 13:04:14.40 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   2brtMedium  AppWorker:a3088b58-780b-4bb8-b65d-e377e7ba4030 worker process is started Exe: AppServerHost.exe Args: /id a3088b58-780b-4bb8-b65d-e377e7ba4030 /convertingService net.pipe://127.0.0.1/a57fa3f9-b3f7-4b45-9860-8fdd6ebcc62d /assembly wacword.dll /type WACWS /IsBatchedTracing True /LogQuota 100 WorkerType: WorkerType1 Directory: c:\windows\system32\inetsrv, pid : 13644, IsSandBoxed: True, UniqueSandBoxSid: S-1-5-26473-19571-45394-1381 
09/18/2014 13:04:14.40 w3wp.exe (0x068C)                      0x20A8 Office Web Apps               Office Viewing Architecture   viozMedium  RemoveWorker isRemoved: True session id : uuid:f8655b88-00a7-40ec-bdf5-457f5fb9f2df;id=1380, Guid: 6e96c591-38f8-4691-897d-588cb92206d1 
09/18/2014 13:04:14.40 w3wp.exe (0x068C)                      0x2150 Office Web Apps               Office Viewing Architecture   4sigMedium  ChildProcess AppServerHost.exe is launched inside worker a3088b58-780b-4bb8-b65d-e377e7ba4030. Pid 13644 
09/18/2014 13:04:14.40 w3wp.exe (0x068C)                      0x2150 Office Web Apps               Office Viewing Architecture   d9hnMedium  NotifyNewChildProcessInWorker has seen AppServerHost.exe in worker a3088b58-780b-4bb8-b65d-e377e7ba4030 
09/18/2014 13:04:14.57 w3wp.exe (0x068C)                      0x1050 Office Web Apps               Office Viewing Architecture   viouMedium  ... registering worker a3088b58-780b-4bb8-b65d-e377e7ba4030 
09/18/2014 13:04:14.60 w3wp.exe (0x068C)                      0x1050 Office Web Apps               Office Viewing Architecture   vioxMedium  Worker a3088b58-780b-4bb8-b65d-e377e7ba4030 is now initialized. 
09/18/2014 13:04:14.60 w3wp.exe (0x068C)                      0x1050 Office Web Apps               Office Viewing Architecture   wyqtMonitorableTask thread crashed System.InvalidOperationException: Calling Post() on 'Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext' resulted in multiple callbacks.  This indicates a problem in 'Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext'.     at System.ServiceModel.Dispatcher.ThreadBehavior.SynchronizationContextCallback(Object state)     at Microsoft.Office.Web.Common.RequestPipe.AppChannelSynchronizationContext.RunTask()    at Microsoft.Office.Web.Common.TaskThread.Run()a3088b58-780b-4bb8-b65d-e377e7ba4030