Try removing `Amxmodx` from the `installed_packages` setting. Then reinstall it. You do not need to restart the computer, you can just close Sublime Text and delete:
- The directory `Packages/User/Package Control.cache`
- And the file `Packages/User/Package Control.last-run`
If still not working, it seems you are hitting a bug on Package Control. To help figure things out, you can enable the debug mode for package control:
https://packagecontrol.io/docs/troubleshooting#Enabling_the_Debug_Log