ATTENZION: this bug was found only for the Windows 7 OS
Users try to access the login dialog of Formowrk's Excel client.
When users press the "Connect" button the application responds with an error.
To fix the bug, you need to access the history of installed system updates and uninstall the update KB4556843 (https://support.microsoft.com/it-it/help/4556843/windows-7-update-kb4556843 )