"Let's try that again. You can't add 'Project Category' calculated field with different expressions to the same object."

Hi There,

We've been updating some of our custom forms and have run into the above error. 

When I try and add the custom form into the Queue Details I get this error and I'm not able to include it in the queue. There's both a matching project and an issue form in the custom form area.

What am I missing?

Thanks,

Wendy