Choosing "Differences..." on the "Reload?" prompt in v15 is effectively the same thing as choosing "No" when using an external difference viewer.

Version 14:
1) File is modified externally.
2) "[file] timestamp has changed. Reload? Yes / No / Differences..."
3) Click "Differences..."
4) External difference viewer loads
5) Close external difference viewer
6) "[file] timestamp has changed. Reload? Yes / No / Differences..."
7) choose Yes or No

Version 15:
1-5) same as above
6) The prompt does not re-appear, so there is no chance to choose "Yes"

Version: 15.0.0.2050
External Difference Viewer Settings:
Executable: C:\Program Files\Beyond Compare 4\BComp.exe
Parameters: %1 %2

In version 15 the internal Difference Viewer will have the the "Reload" button. If you are using an external difference viewer this will not be available. You would need to right-click in the window and select "Revert" from the popup menu. The current file contents or database object source will then be loaded.

We have fixed this for version 15.0.1 when using an external difference viewer.

Thank you!