I have 2 self-written macros "Average" and "8 INT_M". If the macro "Average" is already used in a project, I cannot import the macro "8 INT_M" anymore. The message appears: The macro "8 INT_M" already exists... replace? Yes/No Why is it happening, and how can I import this macro?

This happens because you are trying to import a macro with an already existing ID, though its name and content are different. Most likely, you created one macro, used the command ‘Export macro’, modified this very same macro, and then exported it with a different name. In this case, akYtec ALP assigned an inner ID for the first macro and never changed it even after you had used the Export macro command once again. To overcome this collision, you should have used the command ‘Save macro as…’ before exporting the second macro based on the first one.