Layerslider plugin (sometimes) disables all access to site… for no reason

Hi All and thanks in advance for your help!

I have a WP multisite running 3.9 with The7 theme installed. No strange plugins installed. When editing a slider in the Layerslider plugin (which was included in the theme — fully up to date), from time to time when I try to upload a new image or save the slide, the site (uhpapp.beauxapps.com) becomes inaccessible — I can’t access anything (I can’t access the other site on the multisite (beauxapps.com) or the wp-admin area for either site). Firefox (and all other browsers, even via a data connection on my phone), just load forever.

The file sizes aren’t large (not to mention my php.ini file is setup to accept large files).

I’ve disabled all plugins, repaired database tables, changed themes, etc. The first few times it happened, I repaired the tables and that seemed to work. Now nothing is working.

This error pops up (generated by the Layerslider page I think) when I reload the layerslider page I was working in.

It seems there is a server issue that prevented LayerSlider from saving your work. Please, try to temporary disable themes/plugins, or contact with your hosting provider. Your HTTP server thrown the following error:

[Exception… “Failure” nsresult: “0x80004005 (NS_ERROR_FAILURE)” location: “JS frame :: https://uhpapp.beauxapps.com/wp-admin/load-scripts.php?c=0&load%5B%5D=jquery-core,jquery-migrate,utils,plupload,json2,farbtastic&ver=3.9 :: .send :: line 4” data: no]

How can I solve this? Any idea why this is happening?

***This is strange too: I just took a look at my wp-config file and it’s blank! It was not blank this morning and I haven’t touched it! I think I have a backup of it. I will upload that and see if it solves the problem, but I’d like to know why it went blank in the first place!

Thanks again!

BB