Make sure .Net 3.5 is installed.

I installed 3.5 and activated in server features. Restarted and still getting the error.

Is there anything else I can do or check? We are at a complete stand still without reports.

Sage 300 ERP 2018 on Server 2012 R2

I believe your issue is incompatible Crystal Runtime Engines.

Your options (as I see it) are:
1. Upgrade to Sage 300 2019 or higher (they use the updated runtime engine)
2. Uninstall Crystal 2016 and any 3rd party Crystal utilities (if used) or Crystal redistributables and then re-install Sage 300 to update the required Crystal Runtime