Hi all,
So i was hoping this would be rather simple to do, but its proving a bit infuriating! I’ve gone ahead and opened up the template AR scene, and have that all setup fine so it works on my device. This is all with the native ARCore support that comes with 4.24.
The next step i wanted to take was to change this so it would start image tracking. The first stage was just to get images in there, so I created a new Data Asset of class “ARCandidaeteImage”, added my image in there, set a name and width/height, and then in D_ArSessionConfig, just added 1 new candidate image linked to the one i had just created.
And this has instantly stopped my scene from working. When i load it onto the device the screen is just pure black as if it dosen’t even see the camera, none of the tracking features that were working actually work, and on pressing “Stop AR” in the debug menu it tells me the AR failed to start. I altered the debug print to give me the exact error code its is failing at, but its simply the “Fatal Error” node
Product Version: UE 4.24
Sorry for bumping the thread without any solution to this, but I have the same problem right now with 4.24.1 version. If I omit Candidate Images, everything works fine, but when adding just one candidate image, the screen is constantly black.
Reverting to 4.23.1 solves the issue.
Tried copying the GoogleARCore folder from 4.23.1 to 4.24.1, but, sadly, it didn’t solve the issue.
Really interested in the reason why.
Btw, also tried building from the source, master branch and 4.24.2, but atm it’s a miracle to get them to build, and work properly, even in the basic form.
Hey Saren, i’ve actually got in contact with some guys at Unreal via the UDN. They’ve let me know its a bug in 4.24.1 for ARCore only, so they are going to be patching it out in 4.24.2 hopefully.
Just installed 24.2, and the problem is still there, sadly. The source version can’t even pack the project correctly, due to some callstack errors related to physics, and null meshes. Reading about the news regardin v25, and how they are canceling the support for ES2, I’m going to have like at least 3 different Unreal versions on my computer, lol. This is getting out of hand! 
Thats my issue tracker, looks like they change it to 4.24.3
It’s still here in 4.25. But, first it was constant black screen, not just on the first launch, now it at least works, right?
This seems to be properly working in 4.25
On a second launch, yes. On a first launch, it’s just a black screen. At least it’s tracking something now…hardware: Samsung Galaxy Tab S4.