Swagger Unable to render this definition

报错信息

The provided definition does not specify a valid version field.

Please indicate a valid Swagger or OpenAPI version field. Supported version fields are swagger: "2.0" and those that match openapi: 3.0.n (for example, openapi: 3.0.0).

原因和解决办法

MVC和Gson一起就会有这个错，具体不清楚，把maven的gson依赖去掉可以简单粗暴解决。
或者参考
Gson与SpringMVC一起使用