[Mediawiki-l] Upgrade from 1.4.11 to 1.5.2 Won't Work - Help?

Fri Nov 11 02:34:44 UTC 2005

*I am trying to upgrade from 1.4.11 to 1.5.2 and am getting this error
- I am following the upgrade instructions to load the new files,
delete localsettings.php and run the web installer.  After putting in
the settings and hitting submit I get a page that goes through some
table changes until it runs into this

Fatal error:  Call to undefined function:  wfinverttimestamp() in
/home/comix2/public_html/maintenance/InitialiseMessages.inc on line
120

Does anyone know what I can do?  What I might have done wrong?
***