Lock screen problems

It should not be no.  All Decor8 does is set the image via the api provided by Microsoft.  Once set we are doing nothing so any other changes you made should override it.

Ok so I uninstalled Decor8, restarted, set slideshow on Windows 8.1 PC settings, which worked. Then reinstalled Decor8 and lock screen slideshow still worked. Then reset lock screen image on Decor8 settings, and lock screen image was displayed. Then again set slideshow on Windows 8.1 PC settings - locks screen slideshow did not work - lock screen used image previously set on Decor8 appeared on lock screen. So it looks to me that Deco8 setting in this case supersedes Windows 8.1 PC setting. As long as I do not set a lock screen image on Decor8 after reinstalling Decor8, then lock screen slideshow will work.

Uninstalling Decor8 will not undo the setting for the lock screen, so that step should have done nothing.  When running Decor8 does nothing to the lock screen unless you go into the UI and apply a lockscreen at which point it tells the OS that's the image you want and that's it done.  It isn't possible for it to override the OS setting because it is the OS setting.

Could it be that the OS simply wants a reboot after a lockscreen change to slideshow mode? (uninstalling Decor8 would require a reboot)

Maybe - anyway it's working how I want it to so I'm not going to tinker any more.

I am also having this same exact problem. Just upgraded to Windows 8.1 from 8, and I can't set the lockscreen to play a slideshow no matter how many times I try. It does in fact appear that if you have Decor 8 installed with a previously set lockscreen image, it won't let Windows take over and set it to slideshow.

I have reached maximum activations in Decor8
because I have had to reinstall Windows 8.1 to many times, I'm sorry.
Regards Lars-Inge Bengtsson