MS OFFICE SUBSCRIPTION

HI

I HAVE PURCHASED AN MS OFFICE SUBSCRIPTION FOR 5 PC's / MAC's etc in JUNE 2018

However, on trying to use MS OFFICE on my surface pro today (15 Aug) i get the following error:

Error code: INTERNAL_SERVER_ERROR
Correlation ID: c2c6cdd5-b0c9-4ead-8c12-3dc1ffc89b9c

It does not let me sign in or reconnect using my product code..

Any ideas or thoughts on resolving this will be much appreciated