RAR archive, 186 KB, for the UX32LA board, LN variant, revision 1.1 as given in the name. The name does not say what kind of file is inside, and the compact size suggests boardview rather than a full schematic. Extract it and open the contents in a suitable viewer to locate components and follow nets. A 2.0 revision of the same board circulates separately, so read the revision printed on the PCB before working from this file. A mismatch can put components in the wrong places.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.