Can't modify custom client

[ogirok42]

I want to modify custom client of minecraft b1.7.3 but its not in setup list. So I manually added jars/bin folder and brought my client file here, also i added manifest.json from https://meta.omniarchive.uk/v1/manifest.json to my root folder of RetroMCP and also b.1.7.3 as version.json but it didnt help. Am I doing something wrong or there's no way to modify custom clients?

[PhoenixVX]

Not a bug, please use Discussions tab next time.

Is your custom client reobfuscated according to the same mappings as b1.7.3? I.E. when you look into the JAR, does it have a.class, b.class, or is it more like MathHelper.class?

If the client is reobfuscated according to beta 1.7.3, the proper approach is to setup Beta 1.7.3, then replace the minecraft.jar with your custom client and then decompile. If the decompile fails, it may help you to enable the "Strip generics" option and then re-decompile.

If the custom client has no mappings, then you can remove all the lines in conf/mappings.tiny after the first line and decompile. Otherwise, if the custom client is reobfuscated differently (I.E. different base version or reobfuscated by a different obfuscator), you may have to follow the matching and mapping tutorials from the wiki.

What is Matching?
Creating Mappings