I have the dreaded, "This does not appear to be a Sketchup Model" error - Help Request

This is my first post to the Forum - Hi !

I cannot open a file and am getting the dreaded, “This does not appear to be a Sketchup Model” error".
The file is located on an external hard drive as I work between a desktop at work and a laptop at home. Sorry -no backups on the cloud etc.
Running Windows 10 on both computers with Sketchup Pro 2024 (desktop) & 2025 (laptop)

Any help in recovering the model would be greatly appreciated !
Thanks all