NullPointerException: Registry entry not present: create:copper_shingles

What it looks like in the log

java.lang.NullPointerException: Registry entry not present: create:copper_shingles

How to fix it

1. Open your logs/latest.log file rather than the crash report, scroll above the create:copper_shingles error, and look for the very first ERROR or Exception line to identify which mod actually crashed first.
2. If you have Deep Aether installed on Forge 1.20.1, update both Deep Aether and Create to their latest compatible builds or remove Deep Aether to test if the conflict clears.
3. Check every installed Create addon and update or remove any addon built for a different version of Create (such as mixing Create 0.5.1.f with incompatible addon releases).
4. If latest.log does not clearly point to a single culprit, keep Create enabled and remove your other mods in halves until the game launches to isolate the broken mod.

Check your own log