Duplicate dialog is showing when user saves or cancel saving the file in the chat with one or many users.
Path a)
Path b)
a)
File is saved on your drive, nothing more happens.
b)
Nothing more happens, as you have closed modal dialog.
a) and b)
The same modal dialog opens second time, besides what have you clicked earlier.
Can you please provide more information:
Rocketchat version
Desktop OS and client

I have 2.14.0 version of the Rocket Chat.
Yes, this is related to the https://github.com/RocketChat/Rocket.Chat.Electron/issues/930 issue, although I have always latest version of the Rocket Chat. Issue described there is similar to what people at my workplace are encountering.
@jacekmusial please don't duplicate issues.
If this is related to https://github.com/RocketChat/Rocket.Chat.Electron/issues/930 then follow it up there as it appears to be an issue with the Electron client and not the Rocket.Chat server
@rocket-cat close
Please reopen if this turns out to be an issue with the server itself (check first with different browsers to see if they have the same issue)