Please ensure Outlook is closed before you start.
Right click on the AVG icon on the system tray and select Open. Then go to Menu and select Quarantine
In the Quarantine list you may see multiple instances of BrowserProcessHelper.exe. Right click over the BrowserProcessHelper.exe entries and select Restore and add exception 
Please ensure to only restore these items and not anything else you may see listed. In the screenshot above there are other items listed that the Antivirus has found, these items should NOT be restored
You might to presented with the following error message
if it does move on to the next instance of BrowserProcessHelper and repeat the process - right click and select Restore and add exception
Once done, reopen Outlook and try the Save to Quill buttons again
If this doesn't resolve the issue the Quill Outlook addin will need to be uninstalled via Control Panel add/remove software ,and re-installed again. The file can be downloaded directly from: https://downloads.