Programs won't open

Have Libre office 3.5 installed. Docx files open the Writer program on my pc, but can’t opne .ods files - Calc won’t open itself. Can’t open any of the Libre Office modules via the start menu shortcuts. Can you help. please?

S K Lewicki

If OS Windows:

Reinstall LibreOffice, or use the installer maintenance function Repair
Default program can't find LO on my computer - #2 by manj_k