Hi guys
Suddenly, my project wont load up in unreal 4 anymore. I was actually using it fine last night. I’m getting a crash when the editor is loading up.
Here is a copy of the log that is inside of the Saved folder in my project directory. Any help would be appreciated.
link text
Try to check or delete this file:
Users/Danny/Documents/Unreal Projects/Project_Vine/Content/Blueprints/Rangefinder.uasset
Had same problem. In my case it was blueprint interface causing trouble. I rewrote the entire blueprint and dependencies to not use interfaces and it worked. But just to make sure: try replacing it with older revision (can be found in project folder, usually up to 7 of them) or deleting (moving away) the asset at all.
hi i get this problem a month ago. What is your startup map. When doest it crash? Is in default startup map or when you choose another map? Sorry for my very bad English. 
Ps my Problem was when i tried to open second map in editor it was crashing. My solution was i opened minimal default map then waited 5 min to open my Map.
Can you give me your specs
I had the same thing happen to me. I started a new project and added assets from the broken project one at a time until it broke the new project. It turned out to be a corrupt blueprint.
Good luck.
Try to move Users/Danny/Documents/Unreal Projects/Project_Vine/Content/Blueprints/Rangefinder.uasset completely out of the content directory and post the new crash on startup if it keeps happening.
The crash happens at FileManagerGeneric.cpp:608 in the engine. I looked up the code there and it looks like a read error might lead to a non-deseriazable data. So that the Buffer Array isn’t filled.
Could be that Rangefinder.uasset is damaged. Did the editor crash while saving or something?
If you have source control (and you should if this is a serious project!), try to just check out an older version of Rangefinder.uasset. If you haven’t, you might be in problems and must recreate it.
If you do not have source control, learn from it and get Subversion or Perforce, or Perforce+Git if you like to have the sourcecode in Git and the assets and other files in Perforce, like I do.
Best of luck!
I’d recommend the following steps. 1) Move the project folder (…/My Documents/Unreal Projects/YourProject) to your desktop -The project you were last working on should now no longer be in the “Unreal Projects” folder. 2) Try to launch the UE4. 3) If the editor launches, then a file in your project is corrupt. Likely a Blueprint. Most likely the last blueprint you were working on. 4) If the Editor fails to launch, copy the entire “Unreal Projects” folder somewhere else (ie. The Desktop) to preserve your work. Then uninstall and reinstall the editor and replace the “Unreal Projects” folder WITHOUT the "Your"Project folder you moved in Step 1. 5. Launch UE4. 6) Open any other project besides the one where it crashed. Working? 7) Close editor and move "Your"Project back to “Unreal Projects.” 8) Launch UE4 to any other project but the last one. 9) Make a project known to open to be your default project (the one it will automatically open to every time.) 10) Now, with the editor open on a different project choose: File>Open Project. 11) Open project that last was open before the issue occurred. 12) Does the Engine Crash? No? You’re back in business. Yes? One of the files in your project is corrupt. Try removing the last blueprint you were working on and repeat steps 10-12. Repeat this one blueprint at a time until the project finally opens.
You may have to just run it as an Administrator (the launcher for the Editor that is), I do have a feeling that a fair bit more will have to be done to solve this problem, by all means, try what others have said to do first and then, this as a last resort, I do not have experiences with my editor crashing you see, lucky me, but once again, only try this as a last resort, I am sorry that I cannot offer, I dare say, far more specific help, my apologies.
Were you by any chance using the Matinee editor? I remember there was a bug where a crash on startup would happen if you duplicate the matinee object in the outliner several times.
I had this problem last week. For me, I guessed it was some Blueprint I had worked on last. So browsed to my content folder, removed the .uasset file and started the Editor… Finally the Editor loaded! But with many errors, obviously, since many other assets referenced my now deleted blueprint. But at least the editor loaded so I could fix it.
My problem was that my “problem blueprint” was doing some initialization in the constructor which the editor didn’t like. I could test my project just fine while the editor was already up but didn’t know I had a problem until I shut the editor down and I restarted the next day. I remade my blueprint and moved all my initialization into Begin Play and haven’t had an issue since.
Hi GlacierFox,
As others have said, this appears to be a case of a Blueprint which somehow became corrupted. We’re sorry it happened, and would like to take a look at the Rangefinder.uasset if you’d be willing to share it with us. This way we could find the failure and try to prevent it from happening again.
In the meantime, you should be able to get back into the project by removing that .uasset from your content folder and/or changing your default map which loads (so the Blueprint doesn’t try to load automatically).
Cheers
Same thing happened to me not so long ago and I was freaking out lol What I did was from the Unreal Editor Launcher, I completely deleted the engine that my project was using (4.2.1) and re downloaded it. That fixed my problem. No idea why or how it happened. Hope this helps.
Just delete all your ProjectFolder\Saved* content. You will lost all your project/editor settings, but everything will be fine.
Thanks for the responses guys! It was the Rangefinder Uasset. Basically,I’m an artist and I have the content folders linked up via a home-made source control with my programming friend, it that works pretty well. Turns out, last night, he was working on the Rangefinder blueprint and it totally messed everything up. But yes, he told me to just delete it after troubleshooting for 3 hours while he was lost in the world of Dota 2 
He’s managed to sort it out now thank goodness… Anyway thanks fellas. Programmers ey?
I got same problem, but not same error trying to update a project from 4.3 to 4.5.
The only solution was to create a new project and move all assets to the new version.
Good luck.
Mine keeps crashing. Here’s the first part of the error log that comes up.
Assertion failed: NewMass > 0.f [File:D:\Build++UE4+Release-4.14+Compile\Sync\Engine\Source\Runtime\Engine\Private\PhysicsEngine\BodyInstance.cpp] [Line: 3491]
i have no idea what was the issue but i found that moving stuff to a new project and testing backups there resolved nothing. tried the backups in the original project and the 2nd one worked. again, no idea why.