Hello @jlfranklin , @castletonroad ,
I had the same issue and disabled the following security rules:
920350
920300
949110
980130
911100
920230
920420
Then it worked fine. You can check your modsecurity.log file, check the last access requests from your IP which have been blocked and identify the rule ID which is the issue. On my server, Plesk is running - I can simply disabled a set of rules in the web interface. Not where to do that on other servers, but it might help.
You can also simply go for a less strict rule set (the above is for OWASP).
Hope this helps, regards