after downloading theonyxguy's "Level Shuffle" levelset (from this post) i drag-and-dropped it onto rnd, notably it did not say "game must restart after loading new levelset!" like with most levelsets. afterward, i found a few issues:
1. the custom graphics did not load until i switched to another levelset with its own custom graphics and back
2. if i load a levelset that does not have its own custom graphics (i.e. niko böhm's tutorial), Level Shuffle's custom graphics remain active; this persists until i restart the program
3. the custom menu text never loaded until i restarted the program (i.e. the red strikethrough overlays should match the width of the menu options; "level creator" is renamed "editor" for example)
these problems all went away after restarting the program
problems with drag-and-dropping some levelsets without restarting the game
Moderators: Flumminator, Zomis
Re: problems with drag-and-dropping some levelsets without restarting the game
Oh well, so that means that the program should probably always be restarted after adding a new level set via drag-and-drop. 
Apparently I did not test those scenarios well enough -- as far as I remember (still have to check again), the dialog message to restart the program after adding the new level set is only used when adding a new level set with separate artwork sets packaged as "empty" level sets (a technique that is used by the EMC collection, for example).
So aparently the easiest solution for now is to always ask to restart the program until handling levels that have been added on the fly was improved (or at least when corrextly detecting if a restart is needed or not).
Thanks a lot for your bug report!
Apparently I did not test those scenarios well enough -- as far as I remember (still have to check again), the dialog message to restart the program after adding the new level set is only used when adding a new level set with separate artwork sets packaged as "empty" level sets (a technique that is used by the EMC collection, for example).
So aparently the easiest solution for now is to always ask to restart the program until handling levels that have been added on the fly was improved (or at least when corrextly detecting if a restart is needed or not).
Thanks a lot for your bug report!
Re: problems with drag-and-dropping some levelsets without restarting the game
I have changed the code for now to just ask for a program restart for every level set that has been added by drag-and-drop. 
This should all be fixed for both levels with artwork (as in your example) and for level collections (which already required a program restart before)...
This should all be fixed for both levels with artwork (as in your example) and for level collections (which already required a program restart before)...