Sometimes when opening an entity record in Dynamics CRM, you get the error “Record is Unavailable” and in the log file it contains the following error: “Microsoft.Crm.CrmException: systemform With Id = xxxxxxxxxxx not found”. I am not sure why exactly Dynamics CRM gets into this state and some of the solutions online are to clear your browser cache, etc.
In my case, the only way I was able to get the form to open was to get a link that forced a different form to be opened. You can do this one of 2 ways:
1. Have someone open an entity that you are having issues with and have them email you the link, using the Email Link functionality in the ribbon bar. Or
2. Use the following link and fill in the highlighted sections and enter it in the browser:
https://[dyanmicsCrmUrl]/main.aspx?pagetype=entityrecord&etn=[entityNameHere]&extraqs=formid%3d[GUIDHere]
And here is an example of how that might look:
https://myorgname.crm.dynamics.com/main.aspx?pagetype=entityrecord&etn=account&extraqs=formid%3d6da2bf43-566a-4622-9c06-f350ac6ebf67