[Plugin: NextGEN Gallery] slideshow is no longer working

Weird thing, day ago I tested everything – smoth running, today the slideshow is not working any longer. The only thing I did in between – was creating a new album. – I have no clue what’s wrong.

I deactivated the plugin, uploaded per FTP once more, activated – nothing changed.
I deactivated all Plugins, then only activated NextGen, nothing.
I deleted the album, nothing.
I refreshed Permalinks – nothing.

On the same Shared Host Server All Inkl. NextGen is working fine on another domain. I downloaded the Plugin from there, uploaded it per FTP again to the other Wepspace – nothing.

All I can think of is, deinstall the Plugin, but I have 1632 Pictures in 33 galleries, lot of work to set up once more.

Does anybody know what else I could do? Is it in the database or too many fotos? What have I forgotten to do? Link
Help is very much appreciated – thanks!