Due to issues with a .net framework 4.0 or issues with Quickbooks files you may get Quickbooks event log Error.
This error commonly occurs when the Quickbooks integration manager is not able to connect to Quickbooks.
If you get that event log error and want to know why I get it or what is the causes behind that error, then read that post understand the causes, and learn how to fix the event log error by yourself.https://www.currace.com/quickbooks-event-log-error-4/