Is ubitx_cat.ino in the same directory as the V4.3 code?
There should be 7 files:
Why does this happen? Usually its because if the Arduino-IDE is loading a file for the
first time the file and the directory have to match and if it doesn't it will create it and copy that
one file to the directory. However as your can see the sketch is spread across 7 files all of
which should be in the same directory.
The error message was the compiler saying "hey you told me I need this and cant find it!"..