I know, I'm a little bit irritating... I've made 1-A like a maze of ice. But my level doesn't work, it's driving me nuts! Is there any problem?
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Posted by MiguelMML I know, I'm a little bit irritating... I've made 1-A like a maze of ice. But my level doesn't work, it's driving me nuts! Is there any problem? Be more specific! give more details of what happens. With the information you have given I can not help you...

MiguelMML there is no problem with the editor, it is just your level or your emulator or your flashcard.

Edit1: added "or your emulator or your flashcard"

Edit2:
Extra answers

Nice answer:
Problems with your level could be:
You put sprite 0 which crashes the level (so delete it)
You put too many sprites (over 20 on one screen, so delete some)
The view is too big (so make it smaller)
You put object 1 of tileset 1 which crashes the level (so delete it)
You put a boss a level which is not a boss level (so delete it)
You chose a bad combination of backgrounds (so change it too a good combination of backgrounds)
You added a sprite which needs a path or zone but there is no path or zone for it (so add path or zone or remove sprite)
You do not have a view (so add a view)
You do not have an entrance (so add an entrance)
You do not have a entrance which matches up with a view (so match it up with a view)
You do not have a start entrance which matches up with a start entrance setting in level settings (so match it up)

Mean answer:
JUST TELL US ABOUT YOUR LEVEL!
YOU HAVE THE LEVEL NOT US!
HOW THE HECK ARE WE SUPPOSED TO KNOW WHAT IS WRONG WITH IT?

Hmm... The best way is to use the export level button, then upload it to our awesome incredible uploader, use URL to link the file location.
If you say, I made a icy maze and it didn't work, we CAN NOT see the problem.
Problem might be everywhere!

Other than hiccup's example, I can tell you more:
Maybe you modified overlay0 accidentally so it crashed.
Maybe you put sprite in the sprite-banned area. Some levels can't place specific sprite(s). And sadly we have no data about them.
Maybe you got a crash rom!
Maybe you put a sprite with a non working behavior!

Put a level file, and you can get much more help.
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You have to keep in mind that maybe he was asking if there was a known bug in level editor that made all levels crash.