Weird stretching UE4 interface after running a level?

For some reason, after i have ran my project (in 4.10.1), in Play in editor / Play in selected viewport mode, my UE4 UI will scale and stretch when PIE is activated. as soon as this happens the mouse click position also seems to obtain a weird offset. When running the editor windowed (not maximised) the effect is exaggerated even more.
The attached picture is captured from the screen without scaling in post, this is how my interface will look after i Play in Editor. Play in new window doesnt seem to trigger this bug

for some reason the command “stereo on” seems to trigger this glitch, when i disable the firing of this command the interface doesnt skew up, however i do need this to be active for any standalone build that i play outside of the editor.
Can this please be fixed??

Hello MissStabby,

The reason this occurs is because " stereo on " enables a new setting to r.screenperecentage. That causes the distortion, and thus the blur.

The ‘stereo on’ command is executed too early when the window is not even created yet. Therefore, all the adjustments to the window and viewport are not done (Viewport size should be changed to match the Rift’s resolution, and it uses Window object for that as well).

There is no way to fix it w/o touching the core code. As a workaround, you may execute ‘stereo on’ on Tick Event instead of BeginPlay. A downside of this solution: you will need to do this only once, thus it will be necessary to create a simple singleton logic with a a boolean variable.

Hi ,

I just tried the “on tick event” solution though this doesnt seem to work for me.
Also any delay nodes to further delay the process will only delay when the interface will be warped.

Is there a way to “detect” if the game is being ran as “Play in Editor” or “Simulate” that way i could disable the command for these cases and have it fire whenever it detects it’s being executed as a standalone or (VRpreview) game.

If you would provide a screenshot of how you have your console command " Stereo On " set up. I am attempting to reproduce the same stretching that you are seeing on my end and I am unable to at this time. This way I can eliminate any discrepancies between my test and yours.