libreoffice 5.4.3.2 x64

I have installed yesterday 5.4.3.2 x64 version (i was running x32 version) and since the install, win 10 is not recognising
the apps (writer, calc…) as valid apps. i have to run these app in admin mode with validation at each call to any libreoffice app.
I removed and reinstalled this version without any success.
I tried:
“System File Checker is a utility available in Windows 10 that checks for system file corruption. It’s recommended for advanced users. To run it:”
DISM.exe /Online /Cleanup-image /Restorehealth and sfc /scannow
no success (no problem found)
Is someone has an idea about this problem ?
Rgds,

An antivirus problem? (wild guess)