The official server .jar for 1.17.1 doesn't work, either by doubleclicking it or using a .bat file.
Everytime I try it it says "A JNI error has occurred...."
I've tried starting it with 3 previous versions of Java but no luck there.
On another hand 1.16.4 Modded with Forge works.
Duplicate ofย MC-225505. Please see the moderator note attached to this ticket. ๐