api.openapi-generator.tech are broken

Created by: mpiroc

Bug Report Checklist

Have you provided a full/minimal spec to reproduce the issue?
Have you validated the input using an OpenAPI validator (example)?
What's the version of OpenAPI Generator used?
Have you search for related issues/PRs?
What's the actual output vs expected output?
[Optional] Bounty to sponsor the fix (example)

Description

The POST endpoints throw the same error (a Jackson serialization error) regardless of what language/framework you request, or which OpenAPI document you specify. Example:

{
  "timestamp": "2019-10-04T22:26:58.306Z",
  "status": 500,
  "error": "Internal Server Error",
  "message": "Type definition error: [simple type, class io.swagger.models.auth.SecuritySchemeDefinition]; nested exception is com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of `io.swagger.models.auth.SecuritySchemeDefinition` (no Creators, like default construct, exist): abstract types either need to be mapped to concrete types, have custom deserializer, or contain additional type information\n at [Source: (PushbackInputStream); line: 9, column: 25] (through reference chain: org.openapitools.codegen.online.model.GeneratorInput[\"securityDefinition\"])",
  "path": "/api/gen/clients/typescript-inversify"
}

openapi-generator version

Tested on:

4.2.0-SNAPSHOT
4.1.2

OpenAPI declaration file content or url

https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/modules/openapi-generator/src/test/resources/2_0/petstore.yaml I also tried with several other definitions, both from the OpenAPITools repo, and by third parties.

{
  "authorizationValue": {
    "keyName": "string",
    "type": "string",
    "value": "string"
  },
  "openAPIUrl": "https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/modules/openapi-generator/src/test/resources/2_0/petstore.yaml",
  "options": {},
  "securityDefinition": {
    "description": "string",
    "type": "string"
  },
  "spec": {}
}

Command line used for generation

N/A -- I used http://api.openapi-generator.tech

Steps to reproduce

Visit http://api.openapi-generator.tech in your browser.
Expand the client POST endpoint and enter any language for the 'language' field (tested with typescript-inversify, typescript-nodejs, javascript, and java) OR Expand the server POST endpoint and enter any framework for the 'framework' field.
Enter any language for the 'language' field (tested with typescript-inversify, typescript-nodejs, javascript, and java)
Leave the default request as-is (I also tried pointing it at a number of other OpenAPI definition docs, with the same results).
Click Try