copies of photographs appearing for no reason in my library.

[defaultfhf02f3w6waa]

I keep finding copies of images in my library.  I only use one catalogue.  The copy images have very long file names - for example E11A5D1D-DA61-4322-8C4E-28D6F259A22C_1_105_c.jpeg.  They appear sometimes alternating with the original file and sometimes in blocks following a block of original images.  Sometimes they just appear seemingly randomly in the library.  I have it organised chronologically, but these things can be WAY out of sequence.  I have tried contacting adobe technical dept.  They have no idea.  Has anyone else had this issue?  I am completely stumped.  Cannot think of  a thing I could have done to make it happen.  Camera image storage settings don't seem to make a difference.  some images have never even been opened within lightroom and yet I get a copy.  I do store my images on an external hard drive, but this was happening before I did that.

Has anyone else had this issue.  It is amazingly irritating.

[GoldingD]

From that file name it looks like a library preview file, right click on it and select to show in Finder, what folder is it in?

[defaultfhf02f3w6waa]

In a tree of files coming back to lightroom pictures, this file is held on my external hard drive.

[defaultfhf02f3w6waa]

That is the same base library as the original photographs