2017R2.1 and missing images

When I launch my project, Xojo informs me there are three images missing, but when I click on “select” nothing happens and I haev no apparent way to find out which images are exactly missing. They are collections, apparently, since the project is HiDPI.

I can run the project without it stopping when it encounters the missing images.

Is there any trick that may allow me to locate the missing images ? I don’t really feel like going through all the pictures in the project…