First a little background. On a new disk I installed a new version of Linux. The old disk with the old version is unchanged.
IJ itself is kept on a 3rd disk. It is manually downloaded to that disk, unzipped and launched each time via double clicking on idea.sh in folder bin. This is just how I roll.
OK, so, I downloaded the newest beta of IJ. I unzipped it and double clicked, launching it, like I do. I find I do not want the new interface or the dark theme it comes with. I want my old theme / interface / keymap back. OK fine.
There must be something somewhere on my previous version of Linux (still accessible on the old disk) which told IJ when I launched it as described above what to look like, what theme to use what keymapping what project was open and how the windows were arranged because, before I reinstalled Linux, everything was fine and now nothing is fine, despite launching IJ in the same manner.
I did try the new beta but the new beta knew nothing about my old settings. So I closed that and launched the IJ version which I had been using for months. Unfortunately, it did not return my old settings to me.
All I want is for IJ to be the way it was. I imagine that involves transferring some files and folders from the old linux install on disk A to the linux install on disk B.
I simply do not know what those files and folders might be.