Undo update

After updating to 5.4.4, the project’s level I am working on, is inaccessible due to crash of the editor. 5.4.3 had it’s quirks too but at least, I could get around it and continue. Alas there seems to be no way to undo the update to 5.4.4. Even de-installing 5.4.4 and re-install 5.4.3 is impossible because I don’t see it in the list of versions. It would be a great enhancement if either an update could be reversed, or previous sub-subversion were available for download

Hey there @WillemGr! Generally the hotfixes don’t tend to cause issues mid project (though it’s not impossible), which is why they are pushed automatically to all Epic Game Store binary users. It’s more likely that a windows update, driver update, or other environmental factor has caused the issue. That said, to answer your question, if you want to keep a 5.4.3 installation, you’ll have to build the engine from source. Here’s information on how to get access to the source code, and once you have Github access, the second link will bring you to the releases page where you can retrieve the 5.4.3 source code specifically:

https://www.unrealengine.com/en-US/ue-on-github

https://github.com/EpicGames/UnrealEngine/releases

NO update on Windows, drivers (Nvidia), exactly the same environment. Just an update of Unreal the next day:

While in level that I’m working on:

  • Save all
  • Exit unreal
  • shutdown computer
    Next day:
  • start computer, login
  • Open Epic Games launcher
  • Update Unreal to 5.4.4
  • Start Unreal
  • open project, this opens default level without a problem
  • Open level that I’m working on
  • crash.

I tried another (smaller) level and that worked fine.

It is no problem to push updates / hotfixes, because, as said, there are “never” problems. But as you said, it is not impossible. It is my experience in 40 years of programming of 24/7/365 systems (“downtime is not an option”) , there WILL be such an occasion one day., so you NEED to have a way to revert an update. Rebuilding from scratch may be feasable for you, but not all Unreal users have the kwnoledge, or experience to build a system from scratch. I’m not new to programming but not on a Windows , C++ and Python environment - consider me a newbie in that area. Luckily, I have a Github account, and I installed Visual Studio 2022 (because that was needed for a project I got from Epic), but I doubt it counts for every Unreal user (it’s the charm of Unreal that you don’t need to). do NOT make that assumption !! We’re not all big studios.
In my working days, the version that was updated with a fix would ALWAYS be available in case of the unlikely event the updated version would fail, so it could easily be replaced. It would be wise for Epic to keep the original versions at hand, as a downloadable and installable option - just in case, eventually as a downloadable , zipped installation. Preferably all of the subversion (5.4, 5.4.1,…) so someone that is migrating to a new subversion (5.3.2 → 5.4.4) could revert without the hassle of getting the right version from Github and build it from scratch (with all risks in that step!) to a version that works - or do a stepwise migration.

I understand, was just explaining the common occurrences as it’s usually the most pertinent. In cases where that’s incorrect (happened a good amount in the early 5.x+ hotfixes), I’d have to take a look at the error specifically to see if there was a possible workaround before having the user build a specific version.

I also agree that hotfixes for the binary versions should be stored as well. For such a large project it’s entirely possible that even minor hotfixes can cause issues in some specific use cases.

Could I take a look at the crash context?

What do you need as context? The whole project is 55 Gb zipped. I think you’ll need it all, since it seems that size matters. A smaller level has no issues at all, no matter what mode I view it in. Even the spline- and data asset based PCGs work as intended.

Now for the ‘fun’ part:
I could load the project, selected a smaller level I worked in, set it to “top, wireframe” and switched to the main level. That works but doesn’t show anything.

  • Selected one region to be loaded.
  • Set the view mode to 4 ‘screens’ using the default? , it has ‘perspective, lit’ bottom left and ‘top, wireframe’ bottom right.
    ‘Perspective’ shows nothing, ‘top’ shows the wireframes.
  • Select an asset from the outliner

And behold: Perspective shows it’s contents!!!. Make it a full screen, and it keeps showing. Load another region, and it will show…
Save all, close project, reopen normally, select the level to be shown (the big one), it starts showing all what’s in it. prepares the PCG tasks, it takes some time but then I can move around, but it is slow.
There is a large number of messages of Log D3D12RHI:

LogD3D12RHI: Warning: Descriptor cache ran out of sub allocated descriptor blocks! Moving to Context local View heap strategy
LogD3D12RHI: This should only happen in the Editor where it doesn t matter as much. If it happens in game you should increase the device global heap size!

LogD3D12RHI: Waited for PSO creation for 100.000000ms
(and 200.0000 and 400.00000)

LogD3D12RHI: OnlineHeap RollOver Detected. Increase the heap size to prevent creation of additional heaps

but again, after leaving the system run for a while, moving goes faster.

For now, I hope it will still keeps working as it should. But I don’t consider it solved as it might happen again.

Update:
I can now access the level since all spllne- and data-asset splines have been removed. I can work in it without a problem, until I add a spline- and data-asset based PCG: I added one such a PCG, at first it’s OK, but at some point the perspective+lit window turns ‘blank’ again. Saved all, re-opened the level, no change. Switch to 4-window mode, set top (right bottom) to wireframe and that shows. Next select an asset (in the center of the scene) and perspective shows again, I can open that window in whole screen and go on working.

So my suspicion is that this type of PCG causes problems when generated. Even if clear, it may happen.

Update:
Is isn’t needed to switch to four planes and set any of them to “wireframe”. If the perspective screen turns ‘blank’, select and double-click any object in the outliner, and you will get that asset in view and you can do whatever you like.
However, if the viewport is not blank but errraticly changing when you move your view, this doesn’t work; you’ll need to reopen the level after “save all” (reported Viewport becomes unusable after moving cursor - General / Feedback & Requests - Epic Developer Community Forums (unrealengine.com)

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Another update on thew original problems places where it belongs: Unreal 5.4.4 crashes after load of level - General / Feedback & Requests - Epic Developer Community Forums (unrealengine.com).