Sorry to hear that. I'm very familiar with the kind of syndrome you describe: I'd guess probably most modders spend a little while tearing their hair out trying to find the cause of that crash.
It unfortunately means your XML isn't
quite right. It's very easy to get things fractionally wrong, and XML is a very sensitive format.
First: Carefully look through the text of your blueprints.xml.append file, in particular looking at every tag inside angle brackets <likeThis>. Every "<tag>" should
either end with "/>",
or end with ">" and be matched by a later "</tag>". (But not both!)
If you find any cases where this is wrong, fix them up, re-zip the mod and try repatching.
Second: Make sure that if your blueprint refers to img="myship", then your mod's img/ship/ directory contains each of:
myship_base.png (your ship image)
myship_floor.png (may be transparent)
myship_gib1.png (not actually sure if this is required)
And similarly if your blueprint refers to layout="myship", then your mod's data/ directory contains myship.txt and myship.xml.
If all of those are there, then third: Copy the entirety of your blueprints.xml.append file into a forum post here (enclosed between
[code]...[/code] tags). Post it here and we'll take a look
