1) Could you be more specific please? What program, what calculator, with what linking method? Please also include OS'es and version numbers.
2) If the file is .asm I will explain it to you:
Assembly (For short "asm") is the calculators native programming language, which means it is directly read by the CPU, which means it is basically just a bunch of ones and zeroes that tell your calculator what to do. But since it is uncomfortable to program by typing ones and zeroes, programmers invented the instructions: Now they write in some sort of their own language, they get the .asm file. Then another program grabs the text they wrote and replaces it by said ones and zeroes automatically. This makes programs much more easier to write but requires the program to translate "Human to calculator".
Now what happened is that you grabbed the .asm program and tried to tell the calculator what to do in "human words". It doesn't understand and asks for replacing that by ones and zeroes
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I am not an expert on how to do this, but there are special programs for that available for download, someone else could explain this to you in detail.