Texture problem with custom model

when i start the game with my custom model it comes up with the black and purple square. i checked the console and it said "Unable to resolve texture reference: #missingno in vanillaimproved:item/hammer"

Appreciate any help

*edit* it also says "Unable to load model: 'vanillaimproved:custom/hammer5' referenced from: vanillaimproved:hammer#inventory: net.minecraft.util.ResourceLocationException: Non [a-z0-9/._-] character in path of location: minecraft:Anvil" which bit of the "anvil" is incorrectly named and it also says "Registry Item: Object did not get ID it asked for. Name: vanillaimproved:hammer Expected: 1066 Got: 1067"