Yuris Revenge How can i add Custom Maps to Yuris Revenge

[CommandoX]

Hi, for a long time i have this problem so i hope for an solution now. i downloaded a few cutsom maps for yr and put them into the RA2/Maps/Custom folder but the maps didnt show up in the map selection of the cnc client. I Also put them into the RA2/Maps/Yuri's Revenge folder and in the RA2 folder where the YURI.exe is placed. Still the maps dont show up in the client but there are in the version of the "the first decade" for selection. Is it not possible to play the maps from the cnc client for YR?  

[Grant]

If you've downloaded a map from somewhere, make sure the file extension is renamed to . map

[CommandoX]

I used this link: http://www.mediafire.com/file/e1dlplcow4cuh7e/1137_RA2_%26_YR_Maps_%28unsorted%29.zip/file. So i have to rename all file manually?