Fatal Error

I disabled the AMM plugin and the slideshowCK module that I have now just doesnt actually save. You click save and close and it closes but has a lock next to the module, you click the lock to check in and if you open the module, the slide you added is now gone.

ok please give me an admin acces by email here
www.joomlack.fr/contact

I will check this (probably tomorrow, it is night time here)

for info my answer by email

I made some tests :
- edited the slideshow 257, just hit cancel and get teh fatal error from Advmodulesmanager
- disable the adv_mm plugin
- created a new slideshow module 188 >> added a slide >> save : all is ok, no error and the new slide is saved
- edited the module 257 >> cancel : no error, it works
- enable the plugin adv_mm plugin >> still in the native joomla module manager : Works also
- edited the module 188 with adv_mm >> added a slide and saved : it works
- edited the module 257 with adv_mm, then I get the error when hit "cancel" button (no need to save, cancel also renders this problem)

I see that you have a lot of slides (more than 100) and I think that this is the problem. BUT, the tests confirm that the fatal error does not occur with the native joomla modules manager, so this is really an error to fix in adv_mm.
I have seen that the latest version is 6.2.6, and I was looking in a old version (downloaded the wrong), so there is some code at this line 24

I would suggest to limit the amount of slides, because the visitor will never watch them all, and it will slow down your page load until all the images have been loaded in the page

Thank you for checking on that. However, I disabled the AMM plugin and went into module 257 and deleted slides that I had turned off, hit save and didn't receive an error. The screen just reloaded and brought me back to the module screen. I then went back into module 257 and all of the slides I removed are present again. I don't think its actually "working" when you say its working.

hit save and didn't receive an error.

regarding your initial request, you can see that the fatal error that you get comes from adv_mm, not from the slideshow as there is no error with the normal manager

now for the changes not saved, can you try with a new module ?
also as you have many slides, it means that you already used the module before without problem, right ?