[1.14(.1)] Unable to join non-vanilla servers with custom server core

PaperMC/Waterfall#366 shedaniel/RoughlyEnoughItems#74

When mod with packed Fabric API is installed, i unable to connect “custom-core” servers (BungeeCord, FML, “BeeCord” (hivemc custom core)), vanilla, or just plain Fabric Loader is fine, however.

After “Encrypting”, on “Joining World” connection interrupts with reason Internal Exception: net.minecraft.net_class151: Non [a-z0-9/._-] character in path of location: minecraft:BungeeCord Internal Exception: net.minecraft.net_class151: Non [a-z0-9/._-] character in path of location: minecraft:FML

Happens on 1.14 and 1.14.1

Technical Info:

Launcher: MultiMC5 0.6.5-develop-1308 Fabric API version: v0.2.7+build.127 (in “modpack” included with Autofish, i-am-very-smart, REI) Mods:

  auto-config-1.0.1+mc1.14
  Autofish-0.8.2-fabric-mc1.14
  BBOutlineReloaded-1.0.11-1.14-fabric
  blockmeter-1.0.1
  ClothEvents-0.3.1.23
  CustomSelectionBox-3.2.0
  durabilityviewer-1.14-fabric0.2.7-1.5
  easierchests-1.14-fabric0.2.7-1.3.1
  FabricProxy-1.0.0
  Hwyla-fabric-1.14-1.9.16-60
  i-am-very-smart-1.0.0+mc1.14
  malilib-fabric-1.14.0-0.9.5
  metatips-1.1.4+1.14
  ModMenu-1.5.3-84
  mousewheelie-1.1.5+1.14
  REIAddons-1.1.0
  RoughlyEnoughItems-2.9.110
  tweakeroo-fabric-1.14.0-0.9.3

Logs

[MamiyaOtaru]

fabric-api-0.3.0-pre+build.156 and fabric-resource-loader-v0-0.1.0+f1618918 in gradle: gradlew runClient works fine and I can connect to hypixel. gradlew build, mod and fabric-api-0.3.0-pre+build.156.jar to .minecraft/mods I get the same error as in the screenshot above when trying to connect.

Removing fabric-networking .jar from fabric-api-0.3.0-pre+build.156.jar/META-INF/jars (and others that use it, like fabric-registry-sync etc) again allows me to join hypixel. Can’t say for sure which of them fixes it, as a bunch have to be removed at once to even be able to launch

[liach]

So fabric networking should use some sort of fake identifier for packet id instead of the strict java edition identifier.