So I was FORCED to upgrade to UE5.1 and I got 2 days trying to make it work to no avail. I made my project for 4.27 so I can also save to 5.0, which is stable and working just fine. I successfully finished and tested for 4.27 and started the move to 5.0, which was also successful, with some few minor fixes like lighting but that’s about it. Now it turns out that the Marketplace decided to demand 5.1 files, so I decided to upgrade and it’s just wonky as all hell. Nothing works as it’s supposed to. I tried to upgrade from 4.27 and from 5.0, makes no difference still sucks.
First of all, when building lighting, all blueprints disappear from the level completely, you have to re-open the level to make them re-appear. At which point the Lighting cache you just built disappears and you have re-build it. Guess what happens when you do?
Second [big] thing is that I have 2 maps; A sample level, and an overview level. At first I thought the problem was on the Overview level, as it was actually insta-crashing as I opened it, but then I realized it was more of an issue with maps in general. I finally managed to open somehow the level through trial and error and I STILL have no idea what I did, because it crashed again, so I did the same thing again and it just didn’t work this time. At this point I thought this was a problem with the overview level, so I gave up and decided to create a whole new level from scratch, but turns out it’ll crash no matter what, because I went back to the sample level and it crashed. So it looks like the action of changing maps is what causes the crash for some reason.
I thought that it was the blueprints what caused the crash, but I just deleted them from the project and it still happens.
Am I missing a new secret switch, setting or something?
Ok… so update, although I doubt anyone cares at all from the whopping amount of answers I see here: I tried starting a new project from scratch. And although the crashes didn’t happen in the new project, the frame rate was slow as hell even tho it was just one single cube in the scene. And blueprints disappear anyway during lighting build. So it’s basically this new version rather than my assets. I guess UE is crap now… Wish someone told this to me before I wasted months of my life working on a project that I won’t be able to release.
Yeah, finding the same thing. Migrate a 5.0 project over and most BPs are translucent. Add a light or something to a blueprint, it reappears in the scene. Compile that BP and it disappears again. Materials are messed up and settings in the Sequencer are all jacked. Fun!
Unreal Engine 5.1.0: Same issue with my project. When building the level, all custom blueprint actors disappear. Even if the actors contain nothing but a static mesh component, they still disappear.
Creating a new project with 5.1.0: same issue. Create a simple blueprint actor, with nothing but a cube static mesh. On geometry rebuild it disappears.
The disappearing actors reappear if toggling the visibility of the level (persistent level, in my case), but this bug stops you from building static lights; all blueprint using light source components disappear before lighting build even starts.
Same problem here! We are building a configurator using the Lyra project geometry system. when building the geometry in 5.1 (5.0 works fine!), which consist out of blueprints, everything will disappears including the bp that contains the HDRI so the lighting disappears to… I hope this is not a new ‘function’ causing this but rather a bug that has an easy fix!
Hello, guys, I am currently on a hiatus from this project 'cause it’s honestly depressing. But as soon as I come back to it, I will update everyone on what I find. Failure is not an option. I gotta pay rent and bills.
Regardless, what I found before the hiatus is that the Blueprints are causing the crashes. Another potential thing that I got to eliminate from this particular equation is the GPU.
5.1 demands an RTX 3070 MINIMUM, I had a GTX 1050. I got the minimum requirement GPU, nothing changed. The crashes still happen, albeit the graphics now load faster.
I did some preliminary tests, and when I delete ALL of the blueprints from the file, the crashes don’t happen. At least not immediately.
If anyone else is working on these types of projects and discovers anything, PLEASE share your findings. We CAN figure this out together. [insert Apes Strong Together meme here].
I found out that the issue with disappearing meshes happens only if i use import into level feature… If i import normally to Content drawer there is no issue with disappearing model. But everything that is in blueprint that got created from import into level is faulty
Alright guys, I got important updates:
Today I took another crack at the files again, so here’s what’s cooking: The crash was somehow solved, the Blueprints disappearing are still a problem, and now my virtual textures aren’t working. Which MAY be the problem causing the crash, I am about to delete virtual textures from the other copies of the project to see if THAT is what’s causing the crash.
Another thing that happens is that lighting builds reset after you open levels. I am unsure if that is caused by the disappearing blueprints, since many of the lights ARE in fact inside of a blueprint. That said, the resetting lighting builds DO stop AFTER I delete all blueprints from the level.
So, here’s what I did to fix the crash:
Opened my 4.27 project with 5.1 as cleanly as possible, I let the engine do its thing and didn’t change anything at all. Then saved it.
Next, I made a whole NEW project. Saved that that as well.
I exported/migrated from the converted project in step 1, to the new, empty one.
Opened the new project, now with my precious work. Tested. It doesn’t crash now.
Even tho it worked, very sadly, this new variation didn’t actually export the Runtime Virtual Textures (RVT, for short) data, so I was shown an error; “Fixed up deleted layer weight map”
My RVT’s aren’t working in the new 5.1 version of the project, but also, it ain’t crashing. So there might be something to it.
Edit: Sorry, I pressed Ctrl+Enter and it posted, I had no idea it’d do that.
Ok, so, MY BAD: The RVT’s aren’t damaged, thank god. I just forgot to turn them on in the empty project. Turned them back on, everything works fine.
Now, residual other crap, still not working: Blueprints STILL disappear during lighting build and lighting build STILL resets after changing scenes/levels. The latter was fixed by turning the lights in the blueprints to Movable. I did some tests and static will ALSO work. HOWEVER, there’s a limited number of static lights.
Anyone has solved the disappearing blueprints yet? I didn’t get how to implement @WellCamel’s solution. I tried importing and re-importing, pasting… etc. Nothing works. HOWEVER: For others having the same issue, here’s what HAS WORKED:
Create new project in 5.1. The thing comes with a terrain type thing, right?
Put your blueprints there. Build lighting. SHAZAM! They don’t disappear.
Anyone and anything else, you’re sh*t out of luck, unless anyone has stumbled upon any solution.
I upgraded from a 4.27 project to 5.0, everything worked fine, the main problem with 5.0 was the terrible performance, sudden lag spikes, and ultimately the server travel command didn’t work. I saw that this was fixed in 5.1, so I decided to update from 5.0 to 5.1. However, in this version the performance is even worse, although in theory the server travel problem has been solved. However, I can’t test it because it doesn’t even open a level after I run ‘open’ in the console. I’m trying to adjust settings to see if it solves the problem, but definitely 5.0 and beyond is causing a endless amount of problems.
All I can say is that UE5.1 is a sh*t-show only afforded to use by people with money, 'cause I sure as hell can’t afford the GPU to run it well. The performance dip from 5 to 5.1 is WAY too steep. It’s ridiculous. Plus anything you’ve done in 4.27 is gone to hell; From invalid foliage issues, to crashes, to bricking your entire project. I haven’t had one single positive experience with 5.1 yet. Problem is that the UE Marketplace demands it, so it’s not like I have any options other than sucking it up.
Yes, but if you’ve built an elaborate level with all kinds of cool stuff strapped to it, and then have to RECREATE the whole thing in… essentially the same engine, really, that’s not a solution. To anything. That’s just starting over.
Alright, so I don’t see any more answers here nor more interest. So I’mma go ahead and abandon this thread, BUT feel free to ask questions, I got notifications turned off on my phone and I’m not a social person, so if it takes me 246 years to get to your message, don’t take it personal.
Now, regarding to this issue, the blueprints still disappear during light baking, I have no idea what causes it or how to fix it, unfortunately.
As for the rest, I think I posted a suitable solution, but not sure if it’ll be a “go” with everyone. If it doesn’t work for YOU particularly, share your SNAFU over here and we’ll try to help and/or suggest solutions. To all other peeps with this issue, I wish ya good luck!
Alright. So thought I’d come back and let everyone know that I found the problem. It’s a feature, not a bug. For those having this issue:
I finally solved the problem with the disappearing BluePrints: You need to convert the map to World Partition. So first turn it on in your Project Settings, then CONVERT your level (Go to menu TOOLS, then World Partition, Convert Level), once you do that, SAVE, then go to the World Partition Editor, select the whole thing, then click “Load Region from Selection” and NOW it works.
Obviously the issue goes far deeper than mere spline components, but this is being downplayed in every official avenue. This leads me to suspect that the traditional levels are being phased out, especially if this is fixed by using world partitions. Even the spline component bug report is “unresolved”, with no target version for a fix.
This partially works, when building the whole level (Build All Levels), but the same thing still occurs with static lights. Static lighting does not seems to be supported under World Partition (I can reason why not), so I suppose World Partition fixes the disappearing actors problem, but static lighting is still not feasible in UE 5.1 in any way. With traditional worlds the actors disappear on static lighting build, and with world partition it’s not even supported.