Hi,
At our software development company, we had a big problem caused by Avast (version 151130-0). When we tried to build and execute an older version of our application, it turned out that compilation was possible but execution was not. No error message whatsoever was displayed. It took us a long time until we figured out that Avast was the cause of the problem (we first suspected Microsoft Visual Studio or the hard disk driver to be buggy). By disabling Avast file-system protection for 10 minutes, we managed to execute the built application. Avast did not display a message saying that it was investigating the file for viruses as it usually does. All of this caused great anger in our company.
Of course protection against viruses is important, but so far Avast has been more of a source of trouble than benefit to us, to be honest.