Transcode runner appears to have died. on raspberry Pi 2 as Media Server

Hi,
I've installed flex media server on a raspberry pi 2 using this repository : https://dev2day.de/pms/ . The problem is that playing a moving from flex doesn't work because of the following error :

Jun 02, 2016 17:59:07 [0x67fff400] DEBUG - Request: [192.168.178.24:53471] GET /video/:/transcode/universal/session/zufmmo9fjx/base/00508.ts (72 live)
Jun 02, 2016 17:59:07 [0x67fff400] DEBUG - Asked for segment 508 from session.
Jun 02, 2016 17:59:07 [0x67fff400] WARN - Transcode runner appears to have died.
Jun 02, 2016 17:59:07 [0x67fff400] WARN - Timed out waiting for segment.
Jun 02, 2016 17:59:07 [0x729ff400] DEBUG - Completed: [192.168.178.24:53471] GET /video/:/transcode/universal/session/zufmmo9fjx/base/00508.ts (72 live) 106ms 251 bytes 404

Is there a way to fix this error on raspberry pi ?
Playing through a DNLA client like VLC is working fine ...