Engine crashes whenever I import a heightmap

Hello all. So, I’ve been trying to experiment and learn about levels, streaming and world composition. However, whenever I’m trying to import a heightmap, the project has an 80% chance to crash. The specs for my images are Grayscale/16bit PNG. Am I doing anything wrong or missing something?
Do I have to pay attention to the image’s resolution? I have tried both small (512x512) and large heightmaps (7035x7035), as well as everything in between.
Any other settings I should tweak when importing a heightmap?
I have noticed the engine sets values automatically, but most of the time it heavily distorts the map.
Last but not least, is it possible that my pc can’t handle the process?

Thanks in advance for your help!

PS: I haven’t found any World Composition specific tutorials online. If you have come across anything, let me know!

Update: It seems to be some kind of bug, since now I can’t import any heightmaps. It just crashes.

I am using the 4.12.3 and the same problem occurs in my case too.Please Help ! I tried to do everything like this guy does in this video https://www.youtube.com/watchv=Nl5byRenkf4&index=16&list=PLL0cLF8gjBpqDdMoeid6Vl5roMl6xJQGC