If you click on the 'Storage' icon in the middle of the Web IDE screen, do you see any other files in Storage?
It might be that you already have other files in Storage that are stopping you having space to write your new code in?
You can do
require("Storage").eraseAll()to ensure you totally wipe everything if needed
The problem was that there were no any files seen in the storage via IDE.
But as soon as I executed "eraseAll" command my Espruino became alive again. So, the storage was probably filled with some hidden trash due to some occasion.
Thanks for the help
2v11 (c) 2021 G.Williams
Minification is on with Esprima offline. In the past there were no problems with uploading my code. Smthng went wrong after updating to 2v11 or updating IDE