Hello Sandor,

Thank you for reaching out and I am happy to help!
Please try to completely remove the W3 Total Cache:

1. Check .htaccess File (make backup)
W3TC will create many directives in .htaccess file to control the caching behavior. Each section will start and end with comments like “#BEGIN W3TC Page Cache core” and “#END W3TC Page Cache core”.
Ensure that no residual entries are left over in your .htaccess file after deleting the plugin.
2. Delete wp-content files and folders
– cache folder
– w3tc-config folder
– object-cache.php (if exists)
– advanced-cache.php (if exists)
– db.php (if exists)
– upgrade folder
– delete w3-total-cache folder in wp-content/plugins/ (if exists)
3. Delete Cached Files from CDN (if using CDN)
Besides deleting all the relevant files, if you use CDN then ensure to purge the cached content from your CDN. This is necessary when you enabled minify option in W3TC settings. You should delete the minified and combined scripts and CSS files from your CDN server to avoid the site breaking on the browser.
4. Go to your wp dashboard and re-install W3 Total Cache

If this does not work, you can try downloading the plugin from here, and Upload a Zip File from Your Computer
I hope this helps!
Thanks!