Importing an unsupported image format crashes the application

[Vampiiree]

I decided to try different formats (from Magic TXD export) to see if all of them were supported, but some of them crashed the previewer:

• .tif
• .rwtex
• .pvr
• .dds

Trying to import a .txd file also crashes it (I actually tried it to see if it would load a group of textures automatically instead of loading the textures individually).