Uploaded a new crash report. And here aren't other data packs except for vanilla.
Can be replicated without any other non-vanilla data packs.
In the video, I entered a command first, you can see the change in the contents of the autocomplete box when I typed "exe", "r" or "p". But you, but when I set the value of the set block state such as "lever[face=xxx]", it won't find out all the value about the "xxx".
I will upload a new video about the effect when typing other command
In 20w22a game won't crash but still can't disable the vanilla data pack. Here will be some words in chat says "Reload failed, keeping old data" and "Disabled data pack [vanilla]", but the vanilla data pack is still enabling. I think the new snapshot hasn't solved the problem but made the game not crash.