Fallout 2 mod Mapper crashing when opening a map

[NotNatsuki]

I've been working on a map over the past few days and when I went to open it today the mapper just crashes. I'm able to open other maps, from the game and ones I've made. Is it a lost cause or is there something I can do ?
Any help would be great, I'm new to modding this game

 

[Lexx]

Did you do proto changes?

 

[NotNatsuki]

I'm not sure that is so I'm going to go with no. The last thing I did on the mapper was make a new npc template in librarian mode

 

[Femic]

Did you add the npc to proto.lst?

EDIT:
I meant critter.lst.

 

[NotNatsuki]

Did you add the npc to proto.lst?

No, should I use proto manager to do this, if so how ?

 

[Femic]

Try this https://f3mic.github.io/index.html#New_Critter