I have noticed the following problem with Avast Internet Security 2015.
I have the AV software installed on four systems all with Office 2016/Office365. On two of the systems is HyperV active.
Avast Software is blocking a proper functioning of Office 2016/Office365 on the two systems with HyperV. Executables don’t start, remember Office2016/Office365 is streaming software (AppV5).