If the folder location of the last attachment is not currently accessible, such as a network share requiring an active VPN tunnel, the Attach dialogue window hangs indefinitely. This is using a Windows install of Version 31.6.0. Thunderbird has to be force closed or the computer restarted. The workaround is to use the Advanced tool Config Editor and clear the mail.compose.attach.dir setting before attempting to attach. Is there a more elegant solution? I would expect a timeout to occur triggering an alternate "local" folder/directory to be displayed in the dialogue box as occurs when the setting is empty; or a box to allow the user to select an accessible location. In any case the indefinite hanging is not a good option.