Check the System Information to make sure that all licenses are 8.8 and client's account for current versions.  I had one like this and found that Sage had not updated the client's licenses.  After the account was updated, everything was good.

I contacted support and was advised that it was necessary to go into license manager, enter the new Serial # for SM in the licensing information, then hit refresh which would create the entitlements file based on their subscription.  Once I then went out of sage and back in the error was gone and license manager reported all V8 licensing.   I was told that changing the serial # and hitting refresh will be necessary with each version upgrade.  Not sure if that is true or not.  However this did resolve my issue in this situation.  I have not had to do with before.  I am guessing it has to do with clients that are converting from perpetual to subscription.