[Mediawiki-l] error on All Messages

[david]

I get this error:

Fatal error: Allowed memory size of 20971520 bytes exhausted (tried to
allocate 1310721 bytes) in (...) /wiki/includes/OutputPage.php on line
729

Trying to access "Special:AllMessages" ("Especial:Tots els missatges del
sistema").


With MediaWiki 1.12

Is this something related to my server PHP configuration?

Is strange because I get this errors in my wikis with Semantic Mediawiki
(1.2.6) but not in wikis without this extension.

Greetings.

dvdgmz.