Which version of photoshop and operating system are you using?
Before the photoshop creative cloud versions of cs6, cc and cc 2014, one needs photoshop extended.
Do you have a 3D menu in photoshop?
Could you post a screenshot of yours layers panel with the layers selected before to turned them into a smart object?
No it's not 2014, and yeah one second I just closed it down let me load it back up.
No One seems to understand this issue, I spent 2 hours with Adobe yesterday, sharing my screen and trying to make it work. I even sent them files which they managed to get them to work on their "windows" machine but they didn't try their "Mac", so here is my issue too,
Computer : Macbook Pro 15" Retina Intel Core i7 2.2.MHz, 16gb RAM
S/Ware : Lightroom 5 and 6, Photoshop CC2014(creative cloud member)
OS : Yosemite 10.10.3
Filetypes tried : Sony ARW RAW Files, Canon RAW Files, 8-bit jpeg images.
Workflow : Imported files into LR, edited the files using standard LR adjustments, selected 5 files, edit in ---> Photoshop as Layers. Once in PShop, selected all layers and converted to Smart Object, Layers--->Smart Objects--->Stack mode(greyed out).
I have tried various file types, converted from 16-bit to 8-bit, I have even tried removing all photoshop preferences and also tried changing some settings in PS prefs. I have also tried changing each layer to an individual smart object before merging the layers as a smart object but no joy.
Can anyone help?
I am having the same issue. Did you ever find a solution.
The only difference is that I am running the latest Lightroom CC and Photoshop CC on a PC.