HELP - Error when opening VSTi

Whenever I attempt to open a particular VST (Sylenth 1) in one particular Cubase project, the screen freezes and I eventually have to close cubase from the task manager as it becomes unresponsive. Attached is a snapshot of the error message. This appears to only occur when opening this particular VST in one particular project.
I have updated Cubase to the latest version and clean reinstalled Sylenth.
Again, the issue only seems to occur on this one project as far as I can see, and I’ve never experienced it before.
Any help is appreciated,

Cubase 9.5 Pro