This is the second save this has happened to this week, so I'm hoping it's something that can be fixed, but after updating to 1.5.4 today my character became unable to craft basic items such as Copper Cable, Gears, Yellow Transport Belts (using default recipe, the custom recipe with rubber works), etc.

I had just started a new game yesterday, as an existing game with over 150hrs in it had the same issue over the weekend after one of the other updates. I'm not sure if it's Raw Ores or one of the other Pyanodons Mods, but this one updated today (only other mods I have in are Squeak Through, FNEI, Afraid of the Dark, Alien Biomes and Even Distribution. I have all the Pyanodons mods installed, Coal Processing 1.3.4, Fusion Energy 1.2.8, HighTech 1.2.6, Industry 1.2.9, Petroleum Handling 1.2.5, Raw Ores 1.5.4, Factorio Standard Library 1.2.1).

Starting a new game, everything works, but in the existing saves, I'm unable to access the recipes. I did some digging with the console in the broken saves and the recipes are marked as disabled for some reason? I can't even look them up in FNEI. I considered just console command enabling the recipes, but was unable to work out what 'core' things you should be able to make without research and didn't want to break my overall progression as I'm really enjoying the process of working through the mods.

Hopefully, I'm not the only person with this issue, and it's easy to rectify. Let me know what info I can provide that may help with troubleshooting this issue :)

Sorry should have maybe flagged this as a BUG, doesn't seem to let me edit that though :(

hmm. strange ill look into and see whats going on.

Thank you! I found your notes in the forums about using the pycoaltbaa mod to work around the issue here.
https://forums.factorio.com/viewtopic.php?f=219&t=72693&p=439499#p439498

I can confirm that this fixed the issue if that helps with troubleshooting at all. Super glad to be able to continue to play my save and not have to start again :)

Damn. Well saves me the troubleshooting. Thanks

Just an update on this, one of the mod updates this morning that just ran triggered this bug again (HighTech 1.2.7, Fusion Energy 1.2.9, Coal Processing 1.3.5). Using the pycoaltbaa trick restored the missing recipes. Even Distribution also updated today, I don't believe that changes any recipes, but could also be related.

its 100 percent the migration scripts from pymods. pycoal was updated this morning with one that should have fixed it and the rest should be being* triggered anymore.

if your feeling real spunky. roll pycoalprocessing back a version. make a new save then update pycp to the newest one and see what happens

Thank you thank you! I can confirm that the updates today didn't trigger the issue, so I think it's all fixed up :) Really appreciate the assistance, I honestly thought I had lost hours of gameplay and needed to start again (granted it would have been ok to start again, the spaghetti on my main playthrough is real, hahaha).