How to open .xlr document

New Lenovo PC. Libre Office installed 12-24-2013. Initial opening of .xlr documents worked. Now it requests and app to use and no Libre apps offered

Judging on the extension, this is probably a kind of Excel file. Did Calc open the file the first time?
Could you clean up the question’s tags, please?

Are you using “Open With…” option, going down the menu and selecting LibreOffice? If LibreOffice is not on the list, just browse to the executable. On my machine it’s:

C:\Program Files (x86)\LibreOffice 4.0\program\scalc.exe

check the box “Always open using this program” before hitting OK.

If this is not the answer you were looking for, please provide more details including the exact way your are trying to open the file (i.e. step-by-step procedure you are using).