Problems with PowerNBT...

I'm having a bit of trouble with PowerNBT and mobspawners. Here the deal (plugin is at http://dev.bukkit.org/server-mods/powernbt/).

Previous comment from the author, that was there before I made this mistake (but didn't know was there );

"Server can be crashed if you edit mobspawners. Typo in "EntityID" or "Type" has a terrible effects. This is the most dangerous part. And I have found no other reasons for crashing server."

Then my problem, in reply to that quote;

"This has happened to me... What can I do to fix it (preferably without going into MCEdit if possible, won't be fun to download a multiple gb map and re-upload it)?
I followed this tutorial from your page on mobspawners ([video link]), and it now crashes me whenever I join the server."

Essentially, once I copied the buffer to the mobspawner, it spawned an entity and my client crashed, and now crashes when I try to join. This happens to a large number of people in the surrounding areas (but not everywhere, by the looks of it). I need some way to fix this, preferably without the use of MCEdit... As I said above, downloading an extremely large map, then loading it into MCEdit, then uploading it again isn't exactly ideal, and my last backup of the map is a few days ago. It would also help that I barely know how to use MCEdit...

 

You could possibly try and catch an exception when doing this, removing the spawned Entity? Or maybe, using some hacks like Reflection, hack around stuff, hooking into the entity spawning and cancel it if it goes horribly wrong.
If all this fails, download your (crazy big) map and MCEdit the problem out. It's one of the best solutions.

 

I'm not sure of how to do any of that (I'm not a developer) but load a map into MCEdit. I have the coordinates of the problematic spawner (it's my last logout location).

 

CorruptedHelix
make sure that you know the coordinates of the spawner by console command /nbt x:y:z:world

where x,y,z - coordinates and world - world name/
You must see the spawner tags.
Next commands that should help you:
/nbt x:y:z:world remove (reset tags to default)
/nbt x:y:z:world RequiredPlayerRange = 0 short (do not spawn anything)
/nbt x:y:z:world EntityId = "Cow" (or any other existing mob)

 

It worked, thank you!