The assembly may not be trusted with PERMISSION_SET = EXTERNAL_ACCESS or UNSAFE.

AN error occurred in the Microsoft .NET Framework while trying to load assembly id 65536. The server may be running out of resources, or the assembly may not be trusted with PERMISSION_SET = EXTERNAL_ACCESS or UNSAFE. Run the query again, or check documentation to see how to solve the assembly trust issues. For more information about this error: 
System.IO.FileLoadException: Could not load file or assembly 'microsoft.sqlserver.integrationservices.serve


Solution :

ALTER DATABASE SSISDB SET TRUSTWORTHY ON