Page Not Found error

Update: I have WordPress installed in a subfolder under public_html. Could that be causing the error? Within the Dashboard, the only Gallery page I can view is Overview. Every other page from Add Gallery to About results in the above error.

I’m having just about the same problem, although the specific error I’m getting is “406 Not Acceptable” rather than just “Page not found” (down to a difference in servers, I’d guess). I’m able to view the Overview and the Album page, but I get the 406 error when I try to visit any other part of the plugin’s admin interface. I believe I was running 1.9.10 prior to the upgrade to 1.9.12, and the backend was just fine then.

I’m having a similar problem. Everything else is working fine, but I can’t upload any images through Nextgen. When I go to Upload images, I can select the file, but when I select the gallery before I click Upload, it immediately gives me a 404, the page doesn’t exist. The url it is displaying seems similar to those given above as:
/wp-admin/admin.php?page=nggallery-add-gallery&skipjs[0]=https://www.xxx.com/wp-content/plugins/flickr-set-slideshows/flickr-set-slideshows.js?ver=3.5.1

I’m running the latest version of everything WP 3.5.1, theme= Atahualpa 3.7.12, NextGen is 1.9.12. Key other plugins being run are WPML, Simple PayPal shopping cart, Flickr Set Slideshow and ManageWP. Deactivating all the plugins made no difference. Changing to 2012 theme also made no difference. I’ve not actually tried uploading for a couple of months, so I’ve no idea at what point/which update caused this.

The permissions on the folders are all OK to upload.

I couldn’t find many similar reports when I first searched, but I’ve just searched for “admin.php?page=nggallery-add-gallery&skipjs[0]”
and fund several more people having this problem over the last three months.

I am also facing the issue.

I’ve just returned to this problem to try and resolve it, to no avail.

Still using the same them and plugins as before, except that I’ve no added in Launchpad, everything up to date.

With everything activated, I no longer get a 404 error, I simply constantly get told “Unable to write to directory /xxxxxxxx. Is this directory writable by the server?” All the folders in wp-content have 755 permissions, so I can’t see why there should be a problem. I get the same if Flash is enabled or disable.

I switched to the 2012 theme, with all plugins enabled, same problem, Flash or no Flash.

I deactivated every plugin except NextGen and Launchpad, same problem.

I’ve tried resetting NextGen, and it made no difference.

I’ve tried uploading Nextgen images to another website hosted by my same reseller account and this works fine. So I don’t think that this is a general server problem. Besides, NextGen has been working fine on this website for about 18 months.

No idea what to do next, but at the moment I can’t load any images.

Help.

I noticed a new version of Nextgen has come out today so I updated.

First time I tried to load an image, it worked fine, next time it didn’t.

After several attempts, it seems like if you select the image and then the gallery and immediately hit submit, it works. If you let it think about things after selecting the image and gallery, it decides it likes neither and the boxes are blanked.

So something still isn’t right, but if I hit Submit quickly I can at least upload images.