Alfred keeps asking for Contacts permission

Just like @nobody-in-particular said, your Alfred code was probably changed , therefor the signature that was in place for Alfred is no longer valid. What you have to do is sign the application after the changes to the code.

This worked for me:

sudo codesign --force --deep --sign - "/Applications/Alfred 3.app/Contents/Frameworks/Alfred Framework.framework/Versions/A/Alfred Framework"

我使用的是Alfred 3，需要重新sign一下才行