ID 468721 - Photoshop: Send Thumbnails will not work if Photoshop is in a language other than English or if Background layer is renamed

Problem summary
Send Thumbnails action will not work if Photoshop is in a language other than English, or if the background layer is renamed.

Customer reported version
Flix 6.3.4

Steps to reproduce
1) Go to the Adobe Cloud Preferences > Apps > Installing and change the "Default install language" to be something other than English. For example, we have reproduced this using: Danish, Italian, Mandarin.
2) Now reinstall PS, then open PS and Flix.
3) In PS, click on New Thumbnails then on Send Thumbnails once the template is ready (no need to make changes to it). You will get an error in Flix.

OR

1) In Photoshop, click on New Thumbnails.
2) Rename the layer Background, to anything else.
3) Use Send Thumbnails.

Expected behaviour
9 panels are sent to Flix.

Actual behaviour
One temporary PSD is created in PS and is not closed, Flix Client throws an error, no panels are sent to Flix.

Error states "No such element".​

Workaround
Install Photoshop in English, don't change the Background name.

Reproduced by support

This bug has been reproduced in:
6.3.6 - macOS 10.14 Client - Windows 10 Client

6.1.2 - macOS 10.14 Client - Windows 10 Client

Earliest version tested
6.1.2 - This issue appears to be in all versions of the product