I use liveries manager to install liveries, 800WL Liveries cannot be installed, but the files already there after check the FSX folder. 800,900,900WL can be installed.

What are you trying to say? Do you get an error while installing the liveries?

It's a known problem and have been fixed, I assume a update to the livery manager will come soon, here is info on it and other known issueshttp://forum.avsim.net/topic/341571-pmdg-737ngx-issues-tracking-thread/ If you do a search there is a thread here somewhere where someone figured a pretty easy fix, I personally just edited the aircraft CFG file to get the airlines to show up but it isn't a good idea to mess around with the CFG if you don't know what you're doing.