Hi Wahaj Rashid,
Thank you very much for your reply.
I have downloaded the log file:
Exception Message: An unexpected error occurred.
ErrorCode: -2147220970
HexErrorCode: 0x80040216
ErrorDetails:
ApiExceptionSourceKey: Plugin/Microsoft.Crm.ObjectModel.SyncWorkflowExecutionPlugin
ApiStepKey: ac528ab4-6e86-eb11-b1ad-000d3a3a1b5d
ApiDepthKey: 1
ApiActivityIdKey: f0e642d6-f872-4552-8230-22561910b3f6
ApiPluginSolutionNameKey: System
ApiStepSolutionNameKey: System
ApiExceptionCategory: SystemFailure
ApiExceptionMesageName: UnExpected
ApiExceptionHttpStatusCode: 400
HelpLink: go.microsoft.com/.../
TraceText:
[Microsoft.Crm.ObjectModel: Microsoft.Crm.ObjectModel.SyncWorkflowExecutionPlugin]
[ac528ab4-6e86-eb11-b1ad-000d3a3a1b5d: ]
Activity Id: 2b8e95cf-bc3e-4c4c-9e36-1407391c03f8
And this is what I found in DevTools:

Do you have any suggestions based on the log file or screenshot of dev tools for what I should do?