Hi Gavti,
Please provide more information about your problem like instance version, error log and screen shots because there are many reasons that may cause 500 error :-).
If you are using on-premise instance, you should go to the server and enable the tracing and trigger this issue again and then you will be able to find the trace log under : C\Program file\microsoft dynamics crm\trace.
You could also use tools to get the error log:https://crmdiagtool2011.codeplex.com/
Hope it helps.
Best Regards,
Leo
Hi
Could you please share more details about the error? I assume you are using On-Prem CRM?
If you have access to the server, you could try restarting all the crm services and also doing an IIS reset
If the error still persists, I would check the IIS log, Event Viewer and CRM trace files to get the actual error detail.