Yeah same here couldn't open project in KICad due to it being created in newer version. I have latest ver 8.0.3
there's dozens of ver 8.99 releases
https://downloads.kicad.org/kicad/windows/explore/nightlies
Much prefer to run last stable release as 8.0.3. Sorry for being a pain
No need to apologize, I never even considered that being an issue until now. I run Gentoo Linux and many installers will tear up my system. So I've been building many of my programs(kicad, freecad, prusaslicer, sdr++, ect) from Git sources for over a decade, and they can often be ran in place instead of being installed. Plus it allows me to give back to the OSS community a bit with bug reports, testing, and occasionally being a PITA to developers
When this started it was just a fun diversion that slowly turned into I think I can do better, then to I'm going to do it. If I had intended to go this far I'd started out at a stable release. If I roll back I cannot open it either, nor can I 'save as' a previous version. I assume that any 8.99 would open it. But I don't see anyway out of this other than wait until the next release of Kicad.
Honestly the nightly builds of Kicad are very stable. I'm not sure if you can pull a flatpack or appimage to open the files without installing it, just be careful not to open and save any existing projects you have or you'll create the problem for yourself too. Kicad V9 is stated for Mar 2, 2025, ouch.
I've frozen my git version so if I make any updates it won't prolong the problem. I made an issue about it on the git page.
The schematic is posted and all the PCB fab files are there so it can be cloned if you want to.
Making windows for the face plates tonight.