Button button_file,

I think you mistyped a semicolon here, but I'm pretty sure it's a copy/paste mistake. This is followed by a "void", which explains the error message (C++ compiler errors generally make no sense if you made a typo, so you have to look through to try and find it), but I doubt this is the source of the error, could you post the revised code if this is so?

"Button button_file," was a copy/paste mistake . But if you want i can give you code that is needed (some of header file, some of main  that is about button), or a full code for a further investigation.

Button button_file,

I think you mistyped a semicolon here, but I'm pretty sure it's a copy/paste mistake. This is followed by a "void", which explains the error message (C++ compiler errors generally make no sense if you made a typo, so you have to look through to try and find it), but I doubt this is the source of the error, could you post the revised code if this is so?

"Button button_file," was a copy/paste mistake . But if you want i can give you code that is needed (some of header file, some of main  that is about button) for a further investigation.

Button button_file,

I think you mistyped a semicolon here, but I'm pretty sure it's a copy/paste mistake. This is followed by a "void", which explains the error message (C++ compiler errors generally make no sense if you made a typo, so you have to look through to try and find it), but I doubt this is the source of the error, could you post the revised code if this is so?