Hi! I have no idea. Have you checked status.nintex.com? Maybe there was an issue with the designer services. Also - try to refresh the window. Do you see any errors in developer console?
And then, after you published it, you wanted to add the new variable and it showed you that error?
What is the variable's configuration? Can you share it?
If you refresh the page (try with CTRL+R), start designing the workflow back from the "Gallery" --> "Workflow" and then add the variable - does it still show you the same error?
Can you try to add that variable using a different web browser (BTW: what browser are you using?).
No, I get the error while creating the variable, ignore it and continuw modifing the workflow, save and publish goes fine as well.
Those are the variable si created:
But now after ctrl R it starts working normally again