PHP Warning: Undefined array key in error.log

[Snowhog]

Our error.logs contains thousands of PHP Warning: Undefined array key "keyname" entries.

As of 2025-09-21 20:09:23
(Some of the keynames)

"userid" 976 entries [in ../core/vb/library/user.php on line 5006 and ../core/vb/library/user.php on line 1585]
"lastactivity" 245 entries [in ../core/vb/library/user.php on line 1601]
"privacy_options" 246 entries [in ../core/vb/api/user.php on line 251]
"routeid" 2220 entries [in ../core/vb5/route/legacy/vbcms.php on line 80]

Our forum runs fine, so I assume that as these are only warnings, no harm is actually occurring. But I would like to know why these are happening, and if there is something I can do; if it is actually worth the effort; to 'fix' the causes.

[glennrocksvb]

If those are warnings, then it shouldn't do any harm. Depending on the PHP version you're using, those warnings would become errors that would break the site. Since vB5 is EOL, vBulletin will no longer fix them. But they fixed and continue to fix them in vB6.