Unity hangs instead of entering the play mode

Unity Engine
1

Until recently everything was fine, then while I was playing around with terrains, Unity started hanging each time I click on “Play” button (so that now I can’t play my scene anymore). To clarify “playing around with terrains”: I added the second terrain to the existing one, then removed the second one but made the first one several times larger, and after that made several attempts creating rivers with EasyRoads3D - I started multiple times from scratch but each time first removed the previously created road/river.

First I though that this was the issue with performance, so I tried baking lightmap instead of using real-time lighting, and eventually changed the size of the terrain back to the initial one. However, nothing helped.

I’m using Unity 5.6.2f1, my OS is Windows 10, and I’m creating 3D game for Windows.

Please, tell me how I can deal with the issue.

upd. Here is the project repo: GitHub - malinovsky239/unity-strategy: My first Unity project - elements of 3D RTS/tactical RPG (see Readme for demo video and implementation highlights). I tried committing it, then checking it out to another disk but it didn’t help.

upd 2. However, creating an empty project and running it works perfectly, so it looks like the problem with my big project but not with Unity.

2

Figured the reason of the issue out on my own.

The problem had nothing to do with performance. I got an infinite loop in one of the initializing functions after modifying terrain (I infinitely seeked for the point above 0 whereas my entire terrain at some point became lying on the 0xz plane).