Content Library - Poser Formats ...... gone!
I am using Daz Studio Pro 4.6.0.18 (64 bit) for probably a year now. I use a lot of the free models out there and typically install them in
C:\Users\Public\Documents\My DAZ 3D Library\Runtime
These new items typically show up in my Content Library under the main category of Poser Formats.
I have no idea what happened, but when I click on Poser Formats (in the Content Library tab), I only see something called "My Daz 3D Library" which only holds some textures (materials) for a model I recently installed. Before this happened, I easily had all sorts of subcategories like animals, hair, people, props, textures, and some specific ones to content providers like "3D Universe".
How do I fix this? I do searches for even some of the basic models like Victoria3 and Mihael3, and even those do not come up.
I opened some scenes that I made over 6 months ago, and now i get messages like "Some assets needed to load the file were missing. The content may not work as expected. The following files cound not be found:" followed by a long list with lines like "/Runtime/libraries/!DAZ/Victoria 4/Deltas/Base/InjDeltas.PHMEyeCloseTopL.pz2" After I click OK, I just get some grey cubes that vaguely resemble a robot made out of cardboard boxes.
I've been using computers since the early 90s, and 100's of types of different software, so I know my way around computers but I have to say Daz Studio is the most frustrating program out there.

Comments
Sounds very much like the LAST Poser only content you installed you did a Re-Place runtime instead of a Merge.
That would kill all the files in the Runtime and only put the new ones in it. Nothing will fix that except installing everything you lost.
First of course check that your Content folder is Mapped as Both a DAZ Studio Format folder and a Poser Format folder. If it is not Mapped as Poser as well it will not read Poser content in DAZ Studio.
You haven't accidentaly moved a folder into another one have you? I did that yesterday with my data and runtime folders. Panic set in, but my son came along and found them in another folder.
This happened to me. Strangely, the Daz library was not longer showing under Poser Format. I had been trying to use sword sisterhood mats for historical armor and realized that I could not find it in content library. It was all in the right place in the Windows filesystem in the daz library\runtime\Libraries\Pose\MAT Historical Armor. So I checked the Content Directory manager. Sure enough, all the poser format directories had vanished from the tree. Simply re-added them and all was fine. Thanks for the tip.