So apparently “kiway” is a KiCad internal thing.
My first attempt at resolving this would be to look at line 270 of each file of your project and guess from that if it has something to do with a footprint and take action depending on my findings.
Maybe you can guess to which footprint it is related from the last change you made.
Maybe you can revert to a recent backup without too much worries.
Wait for a response from someone with more knowledge about this.
Thanks for your quick response. Prior to your response, I had found the kiway.cpp file, but I never figured out where the error message was coming from. I just spent about 6 hours tracking the problem down. I use a program called kipart (downloadable via Python pip) to generate my box like schematic footprints. It takes a .csv file for input and generates the appropriate contents for a KiCad .lib file. It does not have very robust error detection. In this particular case, I specified a partial footprint name with the footprint Package nick name only, but without the actual footprint name (e.g. “HR2:”). This caused KiCad 5.0 to have
problems. Of course these file formats will be totally replaced for KiCad 6.0.
For specifying “partial” names use the footprint filters. This will allow kicad to suggest footprints fitting that name during the assignment process instead of you still needing to manually add them without any support at all. See How can i assign a footprint to a symbol?