Whenever I try to use any texture pack with connected textures on 1.20.1 fabric (latest mod version), I get a notification that ''resources reload failed''. It doesn't matter if I enable this mod's texture packs first or what the load order of any of the texture packs I use are. I can enable texture packs without connected textures fine, but the moment I load one with connected textures, I get this notification and my texture packs all get removed (back to the left row). When I remove this mod, the issue disappears.

Moreover, I'm also getting this crash log here, which I believe to be related to this mod. Specifically, some issue with falling gravel. https://pastebin.com/DrW2nRhP

you don't have Lazurite (the Forge Indium port) or Sinytra Connector?
Both will be required to make Continuity work on this Forge version

You must install Indium if you are using Sodium older than 0.6.

I'm neither using forge nor an old Sodium version. I'm using both the latest Fabric and Sodium release for 1.20.1. Sodium includes Indium, so I don't need it anymore. This issue is not resolved. After switching to 1.21.1 with the exact same mods as in 1.20.1, this issue no longer happens.

Btw, it literally says I'm using Fabric in the crash log and I mention I'm using Fabric in the issue title. Where are you getting the idea that I'm using Forge?

The log says you are using Sodium 0.5.13, which is older than 0.6. To be clear, though, Sodium 0.6 or newer does not exist and never will exist for Minecraft 1.20.1. You must install Indium; Sodium does not include it.

I never said you were using Forge. Sasquott's comment is not relevant in this case.