I have written a simple custom indicator and the code compiles without error or warnings. However, there is a Microsoft header file called "sal.h" in which there are two errors.
1) '#pragma' - invalid preprocessor command sal.h 14 1
Given that I didn't write this ("sal.h") I am at a loss as to know a) why this has occurred and b) how to eliminate this error. Does MT4 use its own compiler or does it use a compiler than one has installed on the machine on which one is doing the code development. How is this set up?
Show your code! We cannot guess what is written there unless you show the code.
MT4 Uses its own editor/compiler called MetaEditor! It does not use any external compiler!