What is “NO!” response?

Checked wp_debug as well as my nginx logs and can’t find any errors explaining why I can’t upload some files but others I can. I’ve tested 3 archives of which the following:

file 1 – 3.5M – failed with No!
file 2 – 2.1M – failed with No!
file 3 – under 1M – success!

However when I upload via zip to install a plugin or theme via wp-admin, I can successfully uploaded files greater than 20M.

My php limits are:

memory_limit 512M
post_max_size 100M
upload_max_filesize 100M

I don’t see anything in wp-config.php or php.ini/user.ini that would further limit uploads in any way.

Any direction with how to further troubleshoot this is greatly appreciated. Thx

Hi Philip,

The line ‘NO’ is triggered by any reply from the HTTP server other than a “200 – OK” response. The AJAX handler in question is this.

The alert in the javascript side should definitely be better than a straight ‘NO’. As you can see in the PHP, the server-side code does return an error description, so I’ll have the Javascript alert out this output instead.

You should be able to see what is knocking back your upload if you watch the request in your browser’s network inspector.

Thanks for spotting this one. You’re great!

Kind Regards,
Shane

All I could see in the browser inspector was the source file is admin-ajax.php and the error is a server side 403.

Again, just wondering how I can get to the bottom of this when all the logs I know about include no explanation as to WHY the server is responding with a 403.

I do see the 403’s in the nginx access log however, but thats the same info as whats in the browser.

It does seem to allude to possibly being a file size issue but why in this circumstance does this not apply when other methods also using admin-ajax.php allow larger zip uploads to the same folder?

Still waiting on my server guru to check into it as well…(it’s an instance of easyengine/nginx running off a debian distro)

I’ve also disabled mod_sec just to be sure it isn’t that and also confirmed script execution doesn’t time out for up to 300s and this is occurring fairly fast…within 15-20sec I get 403.

Hmm that’s interesting

403 – Forbidden, all else being the same it suggests Mod Security, however you’ve stated you’ve disabled it. Also as you’ve stated, it will allow larger file uploads, but not for *this* smaller file.

The file you are uploading, is it the same file type as the other two you are attempting to upload? And if nginx isn’t logging any fault in this case, it sounds like nginx is performing it’s job fine and maybe WordPress is knocking it back, so maybe if you could ascertain whether it is doing a hand-off of the request to WordPress, that would be great.

Kind Regards

Phew, finally figured it out. Turns out it was a security plugin that even when disabled, remains in effect.

The plugin in question is WordFence and its Web Application Firewall which bootstraps htaccess rules via a hook in .user.ini and forces an include of the wordfence-waf.php file which itself links to rules that appear to be saved in a “wflogs” folder within the /wp-content/ folder and does not appear to be only “logs”.

Commenting out the line to include the wordfence-waf.php resolved my admin-ajax.php 403 response.

What a PIA WordFence!

Ahh… That’s interesting! It doesn’t make sense to me as to why it was only rejecting the one file though.

If you have a configuration file of sorts, and are able to send me a copy, I would be very interested in looking at it and seeing if there’s anything AceIDE can do to handle it better.

Thanks ??