most probably the installation manager (or studio 4.6) doesn't write the install location into the windows registry or does it different from previous versions - thus the plugin installer isn't able to detect the right location.
the complete manual installation process is as follows:
step 1:
in your user account: C:\Users\***\
create a new folder "OctaneRender"
so you get: C:\Users\***\OctaneRender
here you create a new folder "Cache"
so you have: C:\Users\***\OctaneRender\Cache
now copy the LiveDbPreview folder into the Cache folder
step 2:
go to the daz studio resources dir: C:\Program Files\DAZ 3D\DAZStudio4\resources
create a new folder "OctaneRender"
so you have: C:\Program Files\DAZ 3D\DAZStudio4\resources\OctaneRender
copy the HdriMaps and IesLights folder into this directory
_and_ rename them to HDR (without the "I"!) and IES accordingly
this will get you
C:\Program Files\DAZ 3D\DAZStudio4\resources\OctaneRender\HDR and
C:\Program Files\DAZ 3D\DAZStudio4\resources\OctaneRender\IES
step 3:
copy all the files from "...\OC1.11\x64" into C:\Program Files\DAZ 3D\DAZStudio4\
step 4:
go to the daz studio plugins dir: C:\Program Files\DAZ 3D\DAZStudio4\plugins
create a new folder "OctaneRender"
so you have: C:\Program Files\DAZ 3D\DAZStudio4\plugins\OctaneRender
copy the plordazs.dll from "...\DS4.5.0.0114\x64\plugin" into this new folder
step 5:
copy all files from "...\DS4.5.0.0114\x64\acm" into C:\Program Files\DAZ 3D\DAZStudio4\
all assuming you have a 64 bit DS installed, otherwise you would use the files from the Win32 folders accordingly.
step 6::
copy the "OctaneRender_settings.oczdb" into C:/Users/***/AppData/Roaming/DAZ 3D/
(you may use an existing one instead the one from the installer)
step 7::
copy the octane.dll/.dat/etc. and plugin .dll files from an update into their respective folders.
phew
