Building code in version 12 and switching back to version 10.05 and issues

[OnceKnown]

I was at my cousin's house and I built a code for an assignment with his help, but we currently used the newest version of code blocks on his laptop which was version 12 something but when I came home to build the code again (which worked on his laptop with the version 12) it gave me this message at the bottom when I tried to compile it.

"uses an invalid compiler [YOUR ANSWER IS ALREADY THERE. SEARCH THE FORUMS!] [YOUR ANSWER IS ALREADY THERE. SEARCH THE FORUMS!] [YOUR ANSWER IS ALREADY THERE. SEARCH THE FORUMS!]. Probably the toolchain path within the compiler options is not setup correctly?! Skipping..."

I know I placed the compiler (MinGW) in the right path since it compiled my other codes just fine but this one seemed to keep giving me an error. Is there a way to fix this?

The version of code::blocks I have right now is 10.05. And I'm on a windows 7 ultimate 64 bit.

[gd_on]

Your post is not very clear.
I had such problem with a recent C::B version where the internal name of the compiler, as declared inside the .cbp file, has changed (it was with a fortran software). So, my old cbp project was not directly usable after the C:::B version change.
The solution was simply to choose the correct compiler in the specific compiler project compilation options. Though the name of the compiler chosen in C::B was the same (or almost !), the internal generated name within the cbp file was not exactly the same. That was my problem.
May be it's your problem too, but it's not sure.

gd_on