A very quick question

[Carbonox]

First off, sorry for creating a new thread for this, but I didn't exactly know where in the forum I should ask about this.

It's actually pretty simple. I'm trying to attach an Excel file into my post here, but it's saying that the file is invalid. So how do I make it valid? Thanks in advance

EDIT: Obviously I just had to notice that there's a GTP HelpDesk a bit lower

 

[W3H5]

Check out the help desk part of the site for these kinds of questions, that is the part just lower than this.
Sorry I can't help you personally because I'm a techno dinosaur and know jack about this kind of thing. I'm sure someone here is wise with computer knowledge and can answer your question.

 

[Northstar]

It has to be either a pdf., rar. or a zip. file.

So either convert it into a pdf file or move it to a compressed folder.

 

[Carbonox]

Danke schön, now I managed to attach that.