Yet another "add images to post" problem since 3.6.1

Have you tried:

– deactivating all plugins to see if this resolves the problem. If this works, re-activate the plugins one by one until you find the problematic plugin(s).

– switching to the default theme to rule out any theme-specific problems.

– resetting the plugins folder by FTP or PhpMyAdmin. Sometimes, an apparently inactive plugin can still cause problems.

– re-uploading all files & folders – except the wp-content folder and wp-config.php & root .htaccess files – from a fresh download of WordPress. Make sure that you delete the old copies of files & folder before uploading the new ones.

I have tried deactivating all plugins which affect the media library or post pages.

The theme that I use does not affect the admin section. For admin, I use the standard layout and theme.

I do not believe that suggesting a full reload of everything (thus requiring a re download and reapplication of ALL plugins, themes and other customizations) is a realistic suggestion for an issue in a single location which only triggered with the last WP update.
If the site was unreachable or had some major crashing issue, that seems like a probable likely suggestion, but for a single function, it seems like treating a case of acne by using C4 to blow off your face.

I have tried deactivating all plugins which affect the media library or post pages.

No. You have to deactivate all plugins.

The theme that I use does not affect the admin section.

How do you know that? I can bring the entire admin side of a WordPress site to a shuddering halt via a theme. You have to try switching to the default 203 theme.

I do not believe that suggesting a full reload of everything

There is no magic bullet in these situations. This is just the start of basic troubleshooting and is a process of elimination deliberately designed to locate the root cause as quickly as possible by first removing the most obvious and common culprits via a series of (often) temporary steps.

Do you want to locate and, hopefully, fix the problem on your site? If “yes”, then please help us to help you and carry out the changes that we suggest.

holy moly… Sorry to say this – but this has got to be the most silly support that I have ever seen. I do support for a forum software and a complete undo of every customization and a reload of the site forcing the admin to redo every thing that has taken years to get designed is the **LAST** option, not the first. It seems to be obnoxious in the extreme.

If I have to do what you list, it will literally take me DAYS…
Yes, I need to find the error… however, you have basically just told me to nuke my site and then try to rebuild it.

I’ll do it, if I have to, but there has got to be a better way.

as for your specific suggestions:
Why would I need to deactivate ALL plugins? I understand interactions, but how would a plugin targeting the registration be affecting my post/media? and if it doesn’t (and it shouldn’t!) why would I need to deactivate or remove that plugin?

I am sure that you could design a theme to do just that… but again, if the theme that I am using only affects the front end, why the hell would anything I do with the theme affect the back end? especially since the theme was not updated – but WP was. This seems to point to a WP issue, not a theme issue. If I change the theme, there is no affect to the admin section – but it makes my front end look like crap (which is why I don’t use the “standard” theme to begin with.)

Wht you are suggesting is NOT “basic troubleshooting”. What you are suggesting is a nuclear approach. “It doesn’t work. Nuke everything and start from scratch”

If I have to do what you list, it will literally take me DAYS…

Takes less than 5 minutes. Rename the plugin folder via FTP. Change to default theme using dashboard themes.

this has got to be the most silly support that I have ever seen

Then please feel free to use another WordPress resource.

it will literally take me DAYS

Days? Hmm… it usually takes just a few minutes.

there has got to be a better way.

As I said – welcome to the most basic troubleshooting steps.

Why would I need to deactivate ALL plugins?

You work on a software support forum. You figure it out. Or do you not follow the premise of “remove all variables until you have a known, vanilla, environment”?

how would a plugin targeting the registration be affecting my post/media?

Take a look around these forums. Plugins (and themes) can – and sometimes do – affect all aspects of WordPress. How about an auto-signature plugin that stopped all shortcodes from being parsed across the site? Or a banner plugin that stopped all back end modal windows from functioning? Then there’s the theme that stopped other plugins from working? Would you like me to continue because – believe me – I’ve seen ’em all.

Do you think we make these troubleshooting suggestions wantonly or without any thought? Or could it be that we perhaps might know what we’re doing/asking?

if the theme that I am using only affects the front end

Oh – the innocence of ignorance! If you think a theme can only ever affect the front end of your site than you still have a lot to learn, padawan.

it makes my front end look like crap

what would you prefer? A site that looks (in your words) crap for maybe 10 minutes and is finally fixed. Or a site that looks as it does now but doesn’t work properly. The ball is in your court.

Bottom line: you came here to ask for help – presumably because maybe – just maybe – we know a little more than you do. If you refuse to try out the suggestions that we offer, then, frankly, I don’t see how we can help you.

Now – do you want to try the steps I gave above or not?