too many collision triangles for .37 to handle. if you want to keep it the same ror version then reduce the collision vertices, by alot. If you dont mind using a newer version, .39 allows you to increase that by entering "collision-tris (number here)" before the lines of objects in the .terrn file. This hack will only work in .39, nothing below. Example:
Hillside Offroad Park
HSOP.cfg
w 6.7
0.93, 0.86, 0.76
261.0, 31.8761692047, 392.0, 509.0, 0.10000000149, 680.0, 261.0, 31.8761692047, 389.5
collision-tris 1000000
189.717270, 59.006371, 417.624756, -0.000000, 0.000000, 8.000000, LJ-GN-RockNmd01edit
187.694092, 60.024681, 420.161865, 0.000000, 0.000000, 0.000000, LJ-GN-RockNsm01edit
186.779114, 58.004845, 414.804962, -0.000000, 0.000000, -10.000000, LJ-GN-RockNmd01edit