Not sure when it started but over the last month everyone now can't delete or modify records across the platform. We've spent weeks going through the forums and all google searches but nothing is really popping out.
Event logs are not showing anything.
Server build is Server 2016
CRM Dynamics 2016 build 8.2.28.11
SQL 2016 on server 2016
All systems use HTTPS 443 with valid digicert certs
NOT IFD
First every page gets that ERROR screen which provides NO information. Dev tools on I can see hits 500 hits to /XRMServices/2011/Organization.svc/web
Error details:
<html xmlns="">www.w3.org/.../xhtml"><body><parsererror style="display: block; white-space: pre; border: 2px solid #c77; padding: 0 1em 0 1em; margin: 1em; background-color: #fdd; color: black"><h3>This page contains the following errors:</h3><div style="font-family:monospace;font-size:12px">error on line 1 at column 1: Extra content at the end of the document
</div><h3>Below is a rendering of the page up to the first error.</h3></parsererror></body></html>
If for example we go to "Opportunities" we can create files but can't delete or modify: Same 500 errors. Devtools under CONSOLE shows this:
The user I'm working and testing with has System admin rights.
Not sure where to look next or test but CRM become useless.