Call to undefined function is_super_admin() in /wp-includes/ms-files.php

[verygoode]

After the release of 6.8, we have observed fatals across certain multisites.

Specifically, when certain files are requested. E.g., /example/files/2014/01/img_1234.jpg which reults in HTTP 500 and the fatal error below.

PHP Fatal error:  Uncaught Error: Call to undefined function is_super_admin() in /wordpress/core/6.8/wp-includes/ms-files.php:23
Stack trace:
#0 {main}
  thrown in /wordpress/core/6.8/wp-includes/ms-files.php on line 23

This appears related to https://core.trac.wordpress.org/changeset/59967

ms-files.php leverages define( 'SHORTINIT', true ); which makes is_super_admin() unavailable.

Props @jmdodd for noticing the bump in related fatals.

[desrosj]

Hi @verygoode,

You say "certain multisites". Have you identified anything in common so far with the ones that experience this problem?

[Presskopp]

related: #37616

[jorbin]

wp-includes/capabilities.php can't be loaded with SHORTINT. I think we will need to revert [59967]

[jeremyfelt]

This looks like it will fatal on anything still using ms-files for media, so any WP multisite created before 3.5 and not manually converted after.

I think we will need to revert [59967]

Heavy plus one.

[audrasjb]

Yes I also think the best option is to revert this changeset.

Reverts https://core.trac.wordpress.org/changeset/59967

[jorbin]

Based on this only affecting older multisites or multisites that have manually converted to use ms-files, I think we don't need to rush 6.8.1 out the door.

@verygoode If you are looking to update your multisite to take advantage of the removal of ms-files from 2012, ​https://halfelf.org/2012/dumping-ms-files/ may be helpful.

[johnjamesjacoby]

#63104 is another ms-files.php related ticket, opened on March 15.

Only noting here because it seems highly coincidental.

[peterwilsoncc]

In 60170:

Media: Prevent Multisite fatal error in legacy file rewrites.

Removes a call to the is_super_admin() function in ms-files.php as the function isn't available when using the SHORTINIT feature, causing fatal errors on systems using file rewrites.

Reverts [59967].

Props audrasjb, desrosj, jeremyfelt, johnjamesjacoby, jorbin, presskopp, verygoode, dd32, joemcgill.
See #36803.
Fixes #63285.

[peterwilsoncc]

Reopening for merging [60170] to the 6.8 branch pending another committers review.

[jorbin]

[60170] looks good to backport to the 6.8 branch.

[peterwilsoncc]

In 60171:

Media: Prevent Multisite fatal error in legacy file rewrites.

Removes a call to the is_super_admin() function in ms-files.php as the function isn't available when using the SHORTINIT feature, causing fatal errors on systems using file rewrites.

Reverts [59967].

Reviewed by jorbin.
Merges [60170] to the 6.8 branch.

Props audrasjb, desrosj, jeremyfelt, johnjamesjacoby, jorbin, presskopp, verygoode, dd32, joemcgill.
See #36803.
Fixes #63285.

[neo2k23]

I have the same issue in my multisite that all images are missing in some of the subsites.

But not in all of the subsites. Only some are affected. But the behaviour is not consistent and weird.

First almost all sub websites were affected by this.

Then i restored the complete server and retried and some were ok and some were not. But i had more that were ok than the first time i upgraded wp to 6.8.

I tried again a full restore and got even more websites that were ok. Only 3 left with missing images.

Reverting line 24 in ms-files.php to what it was in wp 6.7.2 fixes the issue for the remaining 3 websites.

     if ( '1' === $current_blog->archived || '1' === $current_blog->spam || '1' === $current_blog->deleted ) {

[pgsmarketing]

Thanks to @neo2k23 - that temporary fix helped my multisite.

[neo2k23]

Replying to pgsmarketing:

Thanks to @neo2k23 - that temporary fix helped my multisite.

it is not my fix.. i just followed above instructions posted by @audrasjb in this link

https://core.trac.wordpress.org/changeset/59967

for which i am gratefull as it fixed the problem.

[jorbin]

6.8.1 RC1 is now available for testing and includes a fix for this issue. Please help test before the final release ​https://make.wordpress.org/core/2025/04/28/wordpress-6-8-1-rc1-is-now-available/