Can not throw new Exception() in workflow of Dynamics 365 (same code of MS dynamic online 2016)

Hi All,

I have an issue as below:

I have a workflow which operates normally with MS Dynamics CRM Online.

However, this workflow cannot operate with Dynamic 365 and the error is shown in the attached picture:

"Unexpected exception from plug-in (Execute): wf_testcode.wf__testcode: System.AggregateException: One or more errors occurred. If you contact support, please provide the technical details."

File "Error Detail": <ErrorCode>-2147220891</ErrorCode>

If I remove all of the following code: "throw new Exception("Error!!!"); the workflow operates normally again.

Please help me solve the issue.

Thank.