Hi @barry, moved onto this forum page after your comments on (Layout viewport is blank after updating) although yesterday I was having the issues with viewport blanking or updating incorrectly the final time I tried to reference update it closed layout without a bugsplat which is now what happens no matter what I do with existing layout files.
I ran the workaround in this Email but if made no difference at my end for existing files.
I did send a 2025 model to layout which allowed me to select it and change scenes however any existing files I have wont let me even select a viewport. I have tried to show this in the video below.
I am having to use LO 2024 to keep working however I am missing the new 2025 features so would love a solution