A friend of mine has a Windows 10, Avast, Viber setup, but the Viber can’t send images while Avast is running. If I deactivate avast for minutest, the images sending immediately. Receiving images, texts is working fine, just sending is not possible.
Is Viber being used in a web browser?
Do you get any error message from Avast when this happens?
Instead of turning off all Avast shields, can you disable Avast shields one at a time and test to find out which specific shield is causing the problem.
When replying can you give information:
Which version of Windows?
Which version of Avast, and whether paid or free?
Any other antivirus/antimalware software installed, present or past?