I'm trying to use al_load_bitmap with some files i created, and whenever i try and use the one i made it will spit out an assertion error and the program crashes but for some reason whenever i try it with a random image it works perfectly fine

What LennyLen said. Also, I believe you are trying to understand the problem so you could avoid it in the future - since, possibly a workaround to this issue is to open the image in question in a software like MS Paint or IrfanView and save it under a differnt format (PNG, ...) and then try opening this converted image using Allegro.
Also please specify does the crash happen at loading time or only on drawing? If it is at drawing time then include in your program (after the loading bit) a check that will verify that the loaded bitmap is not NULL.