While deploying SSIS Packages in SQL Server 2012/2014 you receive the following error
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
One of the reasons is because your SSISDB is a participant in AlwaysOn high availability environment.
Ensure that you are deploying your packages to the Primary node, use the Listener connection name if necessary so that you can validate that you are deploying to the right node.