Our new App release cannot work when Avast is activated

[REDACTED]

Hello,

We are a small team of dev located in Belgium. Our app is used daily by more than 3000 users and is developped in QT.

On most of our members'PC under Windows, we have no problem but... On some Windows 8.1 (Avast 2015 150819-1) we have this :
The new version of our app cannot launch when Avast is activated, we got a Windows error : http://snag.gy/tUAIq.jpg (translation : windows cannot access the specified device path or file you may not have appropriate permissions).

When I shut down Avast, it launch without problem.
If I launch the app as an Administrator, it doesn't solve the problem.

The old version doesn't have this problem : http://www.konkours.com/wahoo/v2/wahoosetup.exe
The new version has this problem, we changed nothing to working repertories of our software : http://www.konkours.com/wahoo/v2/0.9.13/wahoosetup.exe

If I copy our software repertory to Desktop, it solves the issue...

We need some help because we cannot release with such an issue with Avast.

Sincerely,

Pierre from Belgium

[Pondus]

report here  https://support.avast.com