Yah, I was using the 5.99 nightlies via a “kicad-nightly” package on fedora, and after Kicad 6.0 came out, this moved (correctly) to the 6.99 branch, which brought in a whole slew of new changes to the project files, which are… not backward compatible. (Which I also understand… but…)

So, what to do? First, edit the “version” in the top of the file to something like 20211014.

Then try and open the file, see how far along you were and how much got munched….

Try and remove strokes

The following VIM regex will strip all the line settings out. :%s/(stroke.*type solid))// If you had customized lines, sorry, you can’t have that in 6.0 anyway. Try re-opening the file again…

Try also :%s/(stroke.*type default))//

Try and remove thermal angles

more vim regexping…. :%s/(thermal_bridge_angle \d*)//g

That was enough for my file. Hopefully this helps someone…