Exercism CLI not working

I was trying to do PLSQL exercises. So i went to install Exercism CLI but even after successfully installation it is not opening. From then i am receiving regular pop-ups saying that installation failed due to signer certificate mismatch.

What operating system?
What command(s) did you run?
How are you running the CLI command? What exactly does it say in the terminal when you run it?
What exactly does the pop up say?