Is this world gone for good?

[Blacklight9]

My wife has a world that she's been building on for months (and of course despite my telling her to keep backing it up, she never has).  She went to load up the world today, was flying around and suddenly received an "Internal Server Error" that kicked her out.   She then couldn't get back in, constantly getting an "Internal Server Error".

 

So I reset the modpack, and the map re-loaded, but the navigation map that was supposed to be in the corner of the screen was nowhere to be found even when hitting "n".

When the map reloaded, there was a LONG LIST of block ID mismatches.

 

 

I then deleted to delete the whole folder and reload EVERYTHING.  I did so, and when she reloaded the world, she still got the long list of block id mismatches (This list appears now each time the map loads).  The map loaded,  the navigation map was back, but things were strange right off the bat.  When she hit F3, the biome listed was "Plains" when she was clearly over an ocean.  Everywhere she went, the biome type didn't match the biome she was in.  There were chunk slices between biomes as if terrain generation between them was done by different Minecraft versions.  SEVERAL blocks were obviously missing in the jungle biomes and there were floating leaves everywhere.  Several of her builds had LOTS of missing blocks.    Her dial-able portal system is no longer functional.

 

I'm at a loss for what happened here or if this is even fixable.  I fear without a backup, she's screwed.  Any other suggestions other than what I've done?

[Loader]

The bit where you deleted the whole folder - did you take a copy of the world/save before you did that?

 

If you don't have a copy (even corrupted, without the map working and the block id errors and the internal server error message) then there's not a lot that can be done anymore.  If you've got something from before then though then there's a chance.

 

 

Make a thread up on the tracker going through what you did and any logs you have on the error, zip up the world and upload it to dropbox or mediafire (anywhere really) and someone will take a look (might be me, but there's some quick people on there).

[Blacklight9]

I have a copy of the world but I completely deleted the entire Minecraft install and re-installed it.