I’ve been able to isolate it. It will consistently rescale if two grips are moved before the window is able to refresh. Moving one grip and letting it refresh, the scale is retained.
Shouldn’t be an issue with my rig.
Thanks @DaveR & @ateliernab for taking the time to reply, much appreciated.
Thanks for bringing this to our attention. What you are seeing is new behavior in LayOut that we are trying - as of the 2026.2 release - where you are able to continue working on your document while viewport(s) are being rendered. Previously, the application would prevent most operations while a viewport was being rendered. Interestingly, you should still not be able to modify the viewport that is currently rendering, but it seems like you are doing exactly that.
For now, it would be wise to wait until the render has finished before making further changes to the viewport, which is the workaround that you seem to have already discovered yourself!
Adam
It’s good you have the solution.
I would still be interested in seeing your LO file. It sounds like it might do with some streamlining. If you want to share it privately you can send it to me via a PM.
Thanks @adam
This was happening to me too. I was working on a file with just two pages and the simple action of adjusting the size of the viewport became a nightmare: even with Preserve Scale ON, the drawing changed scale by itself and took much longer to do something so simple. It was happening in 26.2.228 and is still on in 26.2.442. What can explain a behavior like this?
What I did to fix it? I suspected the SketchUp file needed some streamlining so I got rid of all furnishings and decoration objects and purged it. Additionally, instead of showing 3D views as viewports I exported those and imported them into LayOut as images. This seemed to solve the problem.
But I still think LayOut should be able to handle heavier files if it is to become a major player in the BIM scene. Until then, one will have to get by with workarounds like this and others like placing plans in a file, sections in another, elevations in another, and so on.
This would certainly help hide the problem, as it will result in much quicker renders of your viewport, so you are less likely to hit that conflict time where a render is running on that viewport while you attempt to make more changes to it.
I agree with you here, as well. And we are doing work on our side to be able to handle heavier files like you are suggesting. Thanks for the feedback, I do hope everyone here feels heard on this.
Adam
@adam Please find a solution for that soon! I am right now working on a LayOut file and the problem persists. It feels like a joke: the moment I turn Preserve Scale ON the viewport changes its size.
Unfortunately, the inserted SketchUp file is not heavy, so I have nothing to do about it except pray.
However, working in 2025 the problem does not happen. It is a workaround but a clunky workflow.
I’m having the same issue- and this is a serious issue. I never had an issue with 2025, now trying to convert a basic cabinet drawing to a layout for the shop is a nightmare, additionally the rendering time for the viewports is stupidly slow. It used to take me about 20 mins to do a basic shop drawing, now it takes about an hour. If I was using a free program it would be understandable, but We pay almost $800 a year for sketchup studio. I don’t understand how sketchup actually goes backwards with updates.
Adding that I am also still having this problem in Pro '26, windows 11. (LO v. 26.2.243 64-bit).
For anyone else pulling their hair out over this: VERY careful resizing and regenerating of viewports, only one side at a time, not by the corner, waiting carefully between regens, seems to be getting the job done. But it’s a painful way to work.
In my case, a small, perfectly working, 3-month old, 3-page NYC department of buildings filing set suddenly became unworkable after saving-as a new file and importing an updated model. Models inexplicably shifting in viewports when changing viewport size, scene views refusing to update and showing weird inexplicable stuff, and scale changes. Check to make sure I’m referencing the model I think I am, and the scenes I think I am. Check for software updates. Purge down model size. Remove extraneous views and layers. Hunt through LO settings to make sure that there is not something I am missing. Thinking that the file has been saved-as too many time and is possibly corrupted, completely rebuild LO file from scratch. Still no. Come to the forum, and start the hunt for help.
@adam Again urging Trimble to make Layout into a robust, stable, quick and dependable tool for real-world professional construction documentation. Compared to the competition your products have so much going for them. But Layout costs me so much time, every time. The above-referenced job is too small to absorb it, and there is no way to justify it when invoicing my clients. As we all do, I need to be paid for my work. Please help me not go back to Autodesk.