There should be an option to have an offline version of studio that allows us to develop offline.
Sometimes, circumstances happen in which developers lose access to the internet for certain periods periods of time, that range from a few hours to weeks or even months.
An offline version of studio would allow developers to not lose progress on projects.
As nice as that would be, the problem becomes the sheer amount of assets that Studio has to stream in from the web when you’re editing a game.
ROBLOX studio did support offline without being able to steam in assets like free decals, or brickparts,
I solved this issue by copying the baseplate and the same few parts over and over again and edited their properties.
I’ve always wanted this.
This was a major problem at REM when we were trying to complete the gamejam. I had to use my mobile data in order to access studio at all.
At REM my studio would open without internet access if I completely disconnected, it just gave a warning saying I wont have things from web. If you just have a poor connection, as was the case before using mobile data, it just gave an error about not being able to connect so I am unsure if it is the case that this was implemented.
can’t use play solo without connection though 
Just never test, it’s probably best that way. I just use periods of no internet studio to build things anyway.
I thought about making a program that acts as a HTTP proxy for studio.
You would just run studio once online so all required files are cached.
Afterwards, if studio requests the file when offline, it would return the cached files.
It would still break stuff and not allow inserting previously uninserted stuff, but at least it works (sort of).
I abandoned this project because of not being able to properly proxy ROBLOX because cURL 'n stuff.
The idea is still something that could be used, if anyone feels like making something like this.