When downloading the extension for Mediawiki 1.34 I get this error while tar unpacking:
gzip: stdin: unexpected end of file
tar: Unexpected EOF in archive
tar: Unexpected EOF in archive
tar: Error is not recoverable: exiting now
Topic on Extension talk:UniversalLanguageSelector
From https://www.mediawiki.org/wiki/Special:ExtensionDistributor?extdistname=UniversalLanguageSelector&extdistversion=REL1_34 I get the link https://extdist.wmflabs.org/dist/extensions/UniversalLanguageSelector-REL1_34-21100eb.tar.gz; locally that expands fine. Are you using that archive or a different one?
Am following the Download link on the right hand side of the page which leads here: https://www.mediawiki.org/wiki/Special:ExtensionDistributor/UniversalLanguageSelector And selecting version 1.34 the downloaded file has that same name, yes. It's being downloaded onto my Windows system, from there I am uploading it to my Ubuntu server and then unpacking it. Haven't had any problems with any other extensions up until now... Well, I just tried again for the third time, and this time it worked, that's strange. I guess we can say this isn't an issue?
It's possible that the file was corrupted when you uploaded it via FTP (or whatever).