I have some automation in a private repo that uses this Action, so thank you for building it!

Starting seven days ago, my automation is running into a problem where the issue is created but the Action throws an error after that. Relevant log details:

ℹ  info      Creating new issue Completely fake issue title
✖  error     An error occurred while creating the issue. This might be caused by a malformed issue title, or a typo in the labels or assignees. Check .github/support-news-template.md!
✖  error     TypeError: (s || "").replace is not a function 
    at escapeData (/node_modules/@actions/core/lib/command.js:66:10)
    at Command.toString (/node_modules/@actions/core/lib/command.js:60:35)
    at Object.issueCommand (/node_modules/@actions/core/lib/command.js:23:30)
    at Object.setOutput (/node_modules/@actions/core/lib/core.js:88:15)
    at Toolkit.run (/index.js:49:10)
    at process._tickCallback (internal/process/next_tick.js:68:7)

It took me a while to figure out what was going wrong because I thought that the issue creation was throwing the error but still succeeding somehow? But inside the catch statement you're calling the actions-toolkit logging infrastructure and the stack trace only shows the actions/toolkit code. So it would appear that this line is hitting the error:

because it is the first line after the issue is created that calls into core.whatever. I suspect that issue.data.number is no longer returning a Number in all cases?

Let me know if you need more information.