OWA (Outlook Web App) Error

I'm in the process of migrating from Exchange 2010 to Exchange 2016 with about 60% of the users migrated. Some users started experiencing "something went wrong" errors when they attempt to log into webmail. The error also showed "Too Many Active Connections" The server application logs were showing ASP.NET event id 1309 errors. I had mentioned these errors to a Microsoft Exchange Engineer and she stated that these are not related to Exchange and can be ignored. Now that some users cannot log in, I opened a Microsoft support case. I was put in contact with the same Engineer. I explained about the “something went wrong” errors some users were experiencing and she emailed me a TechNet article. Since my searching through the Internet and Exchange forums didn’t provide a solution to this issue, I have linked the TechNet article below. This did fix my issue and also resolved the ASP.NET errors on all the servers.

https://social.technet.microsoft.com/wiki/contents/articles/29433.exchange-2013-troubleshooting-something-went-wrong-in-both-owa-and-ecp.aspx