I had similar intermitent problems.  I had to reinstall but did the following changes:

 

Only installed specific content that needs to go in the Poser directory (Daz3d figures and their collection of morphs, Poser Python Scripts, and Effects that used scripting).

All other content was installed in separate runtime folders.  I have content from various Vendors ( I need a database to keep track of my stuff).  Also, when I have a problem with textures and morphs it's easier to troubleshoot.  Use 'Collections' in Poser if your tired of manuevering through directories.

Routinely rutinely run Hard Disk utilities (Defrag & ScanDisk) on a weekly basis or whenever I transfer large batches of files.

Daily scan and update anti-virus.

Daily run OS updates.

Leave a large portion of your hard drive free for virtual memory (cache). You can also set an external drive for your cache, but Pose still leaves some files on your C drive.

When I run a large batch of renders, I'll manually check Poser Cache to delete the old unused files.  When poser renders it leaves files on your pc, similar to caching for web sites.  I've had those files corrupted before and had Poser crash and act funny.

It's a two-fold process.  Maintain the OS/Hardware, and maintain Poser.  PS. AVScan all downloaded content no matter how trivial or small.  I've caught a couple of suspect files already.