: If the repo is down, you can often find the official .deb files for tweaks like AppSync Unified on the developer's Official GitHub Releases Page .
That being said, here are some general potential causes for issues with cydia.akemi.ai:
http://cydia.akemi.ai/
domain is down, Karen often maintains mirrors. You can try adding
: Ensure you don't have AppSync Unified from a different, unofficial repository. Duplicate versions with the same package ID can cause installation failures
The cydia.akemi.ai domain may have an expired or misconfigured SSL certificate. Cydia (especially older versions) is picky about HTTPS. You could try http:// instead, but many servers now force HTTPS.