[World Edit in 1.18]

I'm having the same problem, I'm trying to build something very big but I can't use worldedit.

[[REQUEST] lifesteal plugin]

I tried it but it didn't work, it said "Unsupported File Extension. This file type may not be supported by the text editor, would you like to open it anyway?"

When I opened it it was a bunch of question mark symbols and some random text like 20 pages long.  Help?