I have no problem loading GP using kontakt plugins but the 3rd party kontakt plugins does not load automatically like others when i reopen GP. What am i missing…
More info! 
What OS,
What Kontakt version,
Which 3rd party plugins,
What GP version,
What version of the plugin, VST3?
Was this working before?
Etc.
More info!
What OS,
What Kontakt version,
Which 3rd party plugins,
What GP version,
What version of the plugin, VST3?
Was this working before?
Etc.
This looks that either the plugin doesn’t initialize properly or have some sort of plugin state loading issue.
What happens when you open the Plugin Manager and set the plugin Loading as “Delayed” ?
I don’t think you’re talking about plugins here – the only plugin is actually Kontakt.
If most Kontakt libraries work properly but Synthage doesn’t, then that’s a problem with Synthage
Are you using “full” Kontakt, rather than the Kontakt Player?
Also many third party Kontakt libraries (I think if they do not pay a fee to NI) can only be accessed under the “Files” tab.
Did you save the gig file after you have loaded an instrument or a multi from that 3rd party library into Kontakt?
GP always ask to save file before closing it. And yes i always save my files to make sure.
Per my previous question, can you indicate whether this is happening for all libraries or just for one of them