this is possibly related to your installation of AVG.
Can you please uninstall AVG, restart and try again?
does it happen in internet explorer?
you could also try this fix, but it will disable the scanning in chrome so ensure you reinstall AVG.
Press Start + type Run and then OK > type regedit
then navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Attachments
and then in attachments there is an entry called "ScanWithAntiVirus", type REG_DWORD
double click on it and change the value from 3 to 1, then press enter, close down registyeditor and log out then in again and done