Reached the maximum polygons limit (256). Consider simplifying your mesh.

升级unity 2019.3.0b8后，模型出现了一个新的报错：

Failed to create Convex Mesh from source mesh "Car_1A". Reached the maximum polygons limit (256). Consider simplifying your mesh.

根据报错提示，用建模软件，重新导出模型，都按照三角面去导出。之后问题解决。