Overleaf back to v1

It is not possible to revert a v2 project back to v1. Overleaf has a warning about conversion to v2, which is still in beta, being non-reversible.

You will need to manually copy your LaTeX code into a new v1 project and re-upload any associated files. Alternatively, you can download your v2 ZIP and re-upload it to v1, as a new project.

Once you login, you will get a display with text like this (usually on left corner of screen in Overleaf version 2):

Welcome to the Overleaf v2 beta!

Find out more. To tag or rename your v1 projects, please go back to Overleaf v1.

Go back to v1

Click on v1 link you will be back to version 1 with classic Overleaf homepage.

On a more recent note, there is a folder with the V1 projects and those can be moved to V2 if you want to open them (there is no other way at the moment). When Overleaf acquired Sharelatex there were some issues but I would say they have been mostly fixed and Overleaf V2 works fairly well.