Here is an issue that has long annoyed me; that I was reminded of because of the events in my other thread,  In that thread, I was force to force close Poser, 

When I  had  restarted it, I went to reload the scene I was working on, and thanks to the wonder of Autosave, I had not lost all my work. So I picked the latest saved version and it did the thing that annoys me, it asked me to find a ".obj" file.

The thing was, I had previously found this particular .obj file before (I happened when I loaded a saved figure).  So why oh why didn't it update its location when I saved the scene?  My suspicion is that it retained the name MikiBobHair.obj rather than the mikibobhair.obj name I selected.  Windows is case insensitive but could it be that Poser is not?

I often see this with texture files (Vue in particular); I attribute it to the reorganization of storage I am forced to do every few years because humanity has yet to discover the secret of infinite storage.  Usually with textures it is a one time thing (until the next storage reorg).

If there is a setting I need to set to remediate this condition, I'd appreciate being informed of it. I've learned to save complete texture paths when exporting to .obj (which helps the import into Vue and Blender),  but I'm wondering if there's a similar setting for the .pz3 files, and perhaps one that toggles on case insensitivity,

I have tested using Afrodite Ohki's Inifinite Backdrop: changing the case of the letters in the OBJ's name doesn't seem to be a problem.

Are you sure that you have  only one instance of that OBJ file? I wonder if there's not another one, maybe bad or  empty.
You may very easily check by installing Everything, one of the very best Windows tools. This one instantly find any file on your system using part of a name. And it's free

I mostly run into searching for .obj files when they are not in a library, e.g. they are in a library that is not currently added to Poser.

It was a little strange; Poser dropped me into a folder that contained the correct object, the case wasn’t the same is all. It wouldn’t surprise me at all if I had two cooiesmof somemtjings, in the Curious Lab days I would reinstall each purchased resource into each new version of Poser… 

I've taken to never having two files for Poser with the same name anywhere on my computer unless they're exactly the same. Ran into months of issues with rigging where I'd save my wip Poser file that I was working on, and when I loaded it again Poser was picking up the wip obj from the same folder that my wip rigging file was, with the wrong grouping - the thing would explode when reloading the file and I thought it was some alien bug.

This issue is one of the reasons why I still use Poser Pro 2014 to save my models and products.
In poser 11, if you for example rename an obj file and load the model, Poser can't find it and will ask you to locate the obj. If you do that the model will load perfectly by using the renamed obj file. However if you save/overwrite the model it still saves the old obj file name and/or path.
The other reason I still use Poser Pro 2014 to save my models is that when you save a rigged (character) model in Poser 11, the programmed master parameter control dials won't work for DAZ users. Loading and saving/overwriting it with Poser Pro 2014 will fix that issue.

In addition. One quite easy fix for this (if you don't own an older Poser version or runtime editor tool) is to open the CR2 file with a text editor and rename the obj filename manually. Don't forget to make a backup. The obj reference file is listed twice under for example: figureResFile  :Runtime:Geometries:2nd World:Airplane C-172:C172_Airplane.obj
So use the search function of your text editor and rename both file references.