Hello and welcome to the WeMod community.
Try out these steps. They have resolved the issue in the past for others (including me) who had the same error message as you.
Close WeMod completely via Task Manager (double check under the background processes header too).
Uninstall WeMod via the Add Or Remove Programs tool that comes with all Windows PCs.
Navigate to these directories and make sure they have been deleted, if not manually delete them:
Restart your computer. Once restarted, disable your antivirus.
Download and re-install WeMod through this direct link: https://api.wemod.com/client/download
Add WeMod as an exception in your antivirus before you launch it.
If you have either of the following, there are some additional steps:
If you are using an internet service provided by a school/college/university, you’ll need to use a VPN to download WeMod as there is an additional layer of security that you cannot control. Try Opera browser’s free built-in VPN.
Hopefully this resolves your issue. Let us know if it does or not.