Playon Essential HD

I just bought 2 weeks ago, now I have issues with subtitles..
1) Played movie then click the subtitles then select...nothing came out
2) I add in SRT file, previously works fine but now after select the srt file the subtitles still not come out
3) How to sync the subtitle since some srt file sometime too early or too late
Please someone help me, I m new to this, previously I m using Yamaha BluRay-to-Yamaha AV receiver player then getting tired with cinavie, tried to use media player...

Thanks in Advance