I'm getting this error message after selecting bracketed .NEF images. Just beginning to learn Lightroom. Is there a format issue?
"Unable to merge the photos..please cancel and review your selection"
Could you please let me know the exact version of Lightroom installed on your computer ?
Also which operating system are you working on , Windows or MAC ?
Did you try to select different images and then try to make HDR .
I'm also having the same issue sometimes. LR 6.4 on Win10 Pro 64 bit.
I have version 2015.4 Lightroom CC. Windows 10. Yes, I selected 4 images. Ok, I've just tried selecting again, and have noticed that one of the images must have been an edit I've already done in PS, because it has hdr metadata! Now I know why that set wouldn't merge, and have retried leaving that image out, and it's working now. Thanks!