Using 4.11.2 project worked without issue. Building 4.12 there is a problem which is causing the editor to lock, and lock the computer, requiring a hard reset. Since I have to hit the power button, I have not found a real way to diagnose this issue.
It occurs on some open levels, generally when I launch PIE at the moment when it attempts to spawn a pawn. However it can also occur when not in PIE and simply just flying around certain areas of a level in editor mode. I am assuming this is a rendering problem.
The same problem occurs in 4.14. I have tried merging small fixes from other freeze up bug reports, however no luck. Some advice on how to diagnose this issue would be a great start.
This project you are using, have you updated it to each new iteration of the engine or did you natively build this project inside the 4.12 and/or 4.14 version?
Before you do anything though I would first back up your project folder to an external device if you have not already done so.
Go to File → Cook Contents, and see what the output is, if there are a ton of errors or warnings then those should be addressed first.
I would also try building a new project natively inside 4.14 and then migrating your other project folder over (right click contents folder and migrate over). The cleaner your contents folder is the easier it becomes after multiple times.
Thanks for the reply. The project was created in 4.11.2. I discovered the issue in 4.14, however I did back the project up and then attempted it in a 4.12.5 engine build. The issue occurred in 4.12.5 as it did in 4.14.
I have, for the time being, narrowed the issue down to something specifically related to landscape rendering. I have found deleting the landscape actor prevents the lock. I have tried just removing the landscape material, but the lock still occurs. It might be to do with landscapes that have been manually scaled?
I have tested deleting all of the config files, DDC and intermediate data from my project to give it a clean slate, but it will still lock.