"Windows protected your PC"?
CatchTeX is new, so Microsoft SmartScreen does not know the installer yet and shows a blue warning the first time. The installer is safe: you can check its SHA-256 hash and virus scan on the download page.
- Click "More info" under the warning text.

- Check the app name reads
CatchTeX-Setup-<version>.exe, then click Run anyway.
- Follow the installer. No admin rights are needed if you install for your user only.
Browser blocked the download?
In Edge, open Downloads, hover the file, choose … → Keep → Show more → Keep anyway. In Chrome, choose Keep in the download bar.
Still stuck? Write to [email protected].
CatchTeX