Dynamics 365 Running Slow or not Responding after v9 Upgrade

After an upgrade of a Dynamics 365 instance from v8.2 to v9, many users reported an issue where the Dynamics 365 was not loading, or it was loading the pages very slowly. The users were trying to access Dynamics 365 on web client.

The solution to this problem was to clear the browser cache of the affected users’ machines. Once the cache was cleared the users were able to use Dynamics 365 and load the web pages as normal.