"Installation aborted because the add-on appears to be corrupt." with all theme install attempts

All theme install attempts fail with the same error:-

Installation aborted because the add-on appears to be corrupt.

What’s the problem? How can I overcome this?

Hi @mgarvey18, sorry for the inconvenience! Unfortunately there are a few things that could be triggering this problem. If you are running an antivirus program, could you try disabling it and re-trying the install?

You might also want to check to make sure your operating system’s clock is up to date.

Let me know if either of those suggestions work!