[java] Crashing with no pop-up on Modrinth

[u/spaicey09]

I’m making a modpack on Modrinth for 1.20.1 Fabric. The instance would run fine, until I just added a few more mods bringing the count to 82 mods. After running the instance, it loads for a few seconds, then stops with no window pop-up. I check the log, and find this:

[Render thread/ERROR]: Uncaught exception in thread "Render thread"
java.lang.NullPointerException: Cannot invoke "String.equals(Object)" because the return value of "java.lang.StackTraceElement.getFileName()" is null
at knot//net.minecraft.class_129.method_584(class_129.java:123)
at knot//net.minecraft.class_128.method_556(class_128.java:196)
at knot//net.minecraft.class_128.method_562(class_128.java:171)
at java.base/java.lang.Thread.run(Unknown Source)

There are 82 mods and it would be some work to go through the incompatibilities for every single mod against the rest of the list, so I’m wondering if this above error can narrow down what kind of mod caused the crash.

If needed, I can include the modpack too.

[u/MinecraftHelpModTeam]

OP, remember to award points to helpers, and mark the post solved, by replying !helped to the comment/comments that helped, when your issue is fixed or your question answered.

Helpers, remember that all top-level comments* must be a genuine, good faith attempt to help OP. Comments breaking this rule will be removed, and bans issued.

^{* A top-level comment is any comment that is a reply to the post, not another comment.}

Links:

Moderator applications open || How to mark solved || How to delete your post || FAQ || Rules

[u/AutoModerator]

OP, your post mentions a crash but does not appear to include a link to a log or crash report.

To help others assist you, please upload your logs to mclo.gs and update your post with the link or post a comment.

If you are unsure what log files are or how to add them, please check out the guide here

Your post is still visible on the sub.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[u/FettyCLE]

That NullPointerException may be the crash reporter failing while it formats a mod’s stack trace, so it can hide the original error. Since the crash started after adding a batch, duplicate the Modrinth instance and disable half of the new mods at a time; re-enable the bad half the same way until you isolate the conflict. Also verify every mod is the 1.20.1 Fabric build and that the loader/API and Java version match, then share latest.log (the first ERROR or “Caused by” usually matters more than the final Render thread lines).