Cannot Access Business Rules in my Dynamics CRM Dev Environment

Question

I'm having difficulties in creating / updating business rules. Every time I'm trying to create new Business Rules or Edit the Existing business rules. I'm getting an error without a error code. basically it's not letting me to look or create the business rules and sometimes even the processes(workflows) also.
I'm working on CRM 2016 on-premise (version-8.0.0.1088),I'm having a system Administrator's role. It's really tough to troubleshoot and find a solution for this issue has been struggling for a while with the issue.
I've imported an unmanaged solution recently. It's very annoying, spent a lot of time in researching but still no use, any help much appreciated!.

Error Log Details: (from Trace)

TargetInvocationException: Exception has been thrown by the target of an >invocation. ---> System.IO.FileNotFoundException: Could not load file or >assembly 'log4net, Version=1.2.15.0, Culture=neutral, >PublicKeyToken=669e0ddf0bb1aa2a' or one of its dependencies. The system cannot >find the file specified.

Answer 1

It looks like your custom dll deployed to dynamics crm is dependent on log4net, which is not found in server GAC/merged dll.

Answer 2

thanks to Federico Jousset who have promptly responded to my question. He has suggested me to enable the Trace log feature in CRM (on premise), which I wasn't aware of, and once done, it gave me reason why it was failing.