thumbnails show different preview images from the database

[neal]

This is a recurring problem for me. If there are 200 files in a folder, at least 10% show a preview and viewer image that is not the same as the selected thumbnail. It is showing an image from some other file in the database. I have tried "force update" and update cache only. I  have not tried reloading metadata. Nothing fixes this problem.
Neal

[Mario]

This sounds like you use versioning and proxy images?
This would explain that?

Tip: Check the Version panel for one of the problem files to see if there is a proxy image in use.
See also Visual Proxy in the Viewer help (similar option also for the Quick View Panel, in the context menu).

[neal]

No version or proxy problem. I find the only thing that works is to copy the image, open the copy in Photoshop, save as itself and then import it into the original location.

[Mario]

You did not tell us which file format you are using or what your workflow is.

IMatch is using an embedded preview / composite image or the thumbnail, if large enough.
Maybe these files have different previews/thumbnails than the 'real' image, for some reason?

Do you have a sample image which exhibits this problem so we can have a look?