Cannot launch NeoForge 1.21

[leagris]

What Operating System

Linux (Other)

Debug Code

FTB-DBGOLIFEZEWER

Describe the bug

ATM10 pack crashes before even starting

Note that the pack works perfectly fine with Prism Launcher.

Steps to reproduce

Install AlltheMods 10
Try to launch
Crashes very early

Expected behaviour

Should work

Screenshots

No response

Additional information

[FTB APP][INFO] Pre-Start Tasks
[FTB APP][INFO] Pre-Start Tasks Complete
[FTB APP][INFO] Validate Java Runtime
[FTB APP][INFO] Java Runtime Validated
[FTB APP][INFO] Validate assets
[FTB APP][INFO] Assets Validated
[FTB APP][INFO] Validate libraries
[FTB APP][INFO] Libraries Validated
[FTB APP][INFO] Validate client
[FTB APP][INFO] Client Validated
[FTB APP][INFO] Extract natives
[FTB APP][INFO] Natives Extracted
[FTB APP][INFO] Prepare process
[FTB APP][INFO] Process Prepared
OpenJDK 64-Bit Server VM warning: Sharing is only supported for boot loader classes because bootstrap classpath has been appended
Exception in thread "main" java.lang.module.ResolutionException: Modules org.apache.logging.log4j.slf4j2.impl and org.apache.logging.log4j.slf4j export package org.apache.logging.slf4j to module net.neoforged.mergetool.api
	at java.base/java.lang.module.Resolver.resolveFail(Resolver.java:900)
	at java.base/java.lang.module.Resolver.failTwoSuppliers(Resolver.java:814)
	at java.base/java.lang.module.Resolver.checkExportSuppliers(Resolver.java:754)
	at java.base/java.lang.module.Resolver.finish(Resolver.java:380)
	at java.base/java.lang.module.Configuration.<init>(Configuration.java:139)
	at java.base/java.lang.module.Configuration.resolveAndBind(Configuration.java:493)
	at java.base/java.lang.module.Configuration.resolveAndBind(Configuration.java:297)
	at [email protected]/cpw.mods.bootstraplauncher.BootstrapLauncher.run(BootstrapLauncher.java:196)
	at [email protected]/cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:69)

[jerry1333]

And if You change resolution for something normal getting just this:

[FTB APP][INFO] Pre-Start Tasks
[FTB APP][INFO] Pre-Start Tasks Complete
[FTB APP][INFO] Validate Java Runtime
[FTB APP][INFO] Java Runtime Validated
[FTB APP][INFO] Validate assets
[FTB APP][INFO] Assets Validated
[FTB APP][INFO] Validate libraries
[FTB APP][INFO] Libraries Validated
[FTB APP][INFO] Validate client
[FTB APP][INFO] Client Validated
[FTB APP][INFO] Extract natives
[FTB APP][INFO] Natives Extracted
[FTB APP][INFO] Prepare process
[FTB APP][INFO] Process Prepared
OpenJDK 64-Bit Server VM warning: Sharing is only supported for boot loader classes because bootstrap classpath has been appended

[Mekanofreak]

Can confirm also getting this issue and that the pack is working fine using the curseforge app, Prism and ATLauncher.

[Gaz492]

So vanilla 1.21 works but as soon as I create a neoforge 1.21 instance it also runs into the issue you are running into.
Fabric and forge work fine, so this is only an issue with neoforge modpacks.

[Gaz492]

For those using the standalone electron version of the FTB App this issue should be fixed now.
For overwolf, we have set this to be gradually released.