Description: The process was terminated due to an unhandled exception. Exception Info: System.CannotUnloadAppDomainException

Question

After a user closed the application. If the user have not had a reboot. Next time when this user try to open the application will have an error : The * application cannot start due to error: Another instance of the * application running

Investigate the windows event logs we found the following 2 events straight after user closed the application

Application: *.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.CannotUnloadAppDomainException
   at System.AppDomain.Unload(System.AppDomain)
   at Microsoft.ReportingServices.RefCountedAppDomain.Dispose()
   at Microsoft.Reporting.WinForms.LocalReport+ReportRuntimeSetupHandler.ReleaseSandboxAppDomain()
   at Microsoft.Reporting.WinForms.LocalReport.Dispose()
   at Microsoft.Reporting.WinForms.ReportInfo.Dispose()
   at Microsoft.Reporting.WinForms.ReportHierarchy.Clear()
   at Microsoft.Reporting.WinForms.ReportViewer.Dispose(Boolean)
   at System.ComponentModel.Component.Finalize()

&

Faulting application name: *.exe, version: *, time stamp: 0x62689e99
Faulting module name: KERNELBASE.dll, version: 10.0.18362.997, time stamp: 0x91b9349a
Exception code: 0xe0434352
Fault offset: 0x000000000003a719
Faulting process id: 0x2680
Faulting application start time: 0x01d865c193ffbd40
Faulting application path: exe file location
Faulting module path: C:\\Windows\\System32\\KERNELBASE.dll
Report Id: 723d10d5-0b8a-416a-8f68-92588e274303
Faulting package full name: 
Faulting package-relative application ID:

Pretty struggling at the moment, and any ideas appreciated, thank you