Something got blocked by your antivirus or firewall. A quick search on Google shows many Steam threads with this error for many games.
Open up your antivirus and check the quarantined / blocked list. Search for anything related to the game and then unblock it. Or if your antivirus already deleted it, you’ll probably have to verify the integrity again or even reinstall from scratch. You’ll then have to add that item as an exception in your antivirus. It’s not a WeMod or Steam issue, but an antivirus issue.
You’ll probably also need to follow this guide as well: How to white-list WeMod in BitDefender!
BitDefender is a trigger-happy cowboy that likes to block legit stuff. I’ve seen a screenshot here on this forum of BitDefender blocking someone’s command prompt program from running and another screenshot where it was also blocking a critical service that Windows 10 relies on to work properly. There are also reports online of BitDefender interfering with extremely important security features such as System Restore. I’d advise switching your antivirus to something a bit more intelligent. Sorry but BitDefender is the Mr Bean of antiviruses. Here’s a picture of BitDefender in real life (click).
Here’s one of the many examples of the threads I found on Steam where someone has the same issue as you: https://steamcommunity.com/app/629760/discussions/0/1651043958639374870/