Blockquote
I have tried both these formats and that hasn’t made a difference
“and if you have masks file there, then it should be named 20240513_X-001.exr.”
When I use the default RC export setting it is creating the “depth.exr” and “jpg.mask” and I appear to be unable to change that in the Depth and Mask Export persona settings. See below for settings used. (Note Export Location has been deliberately changed for data security reasons).
If you want to use this file name: 20240513_X-001.jpg.mask, then it should be in the same folder as original images and imported into new project in one step.
This was the way I attempted to import the images into a new project to begin with. This caused my original problem of brining the mask files in as images rather than a linked layer to the texture/geometry images.