Kodi – Inconsistant Playback – Files visible, but no playback possible

Hi, Im new to Kodi,and have been using a my media play on and off. Atm i find while browsing media files, that it will load up streaming selecitons, but as as soon
as a selection is made, the file will simply not playback. It has worked in the past, so am completely lost as to what is going on. I have reloaded my repositries, but
no luck. Any help would be much appreciated.