As a thought - are your database and SSRS instance on the same SQL Instance? If not, did you update both SSRS instance and your database instance?
it sounds to me like the SQL instance hosting the database got updated but the SQL instance hosting SSRS did not.
The above is all just my opinion on what you should do.
As with all advice you find on a random internet forum - you shouldn't blindly follow it. Always test on a test server to see if there is negative side effects before making changes to live!
I recommend you NEVER run "random code" you found online on any system you care about UNLESS you understand and can verify the code OR you don't care if the code trashes your system.