Since 1.3.5 /v3/api-docs cannot be found anymore

[sticksen]

Describe the bug
I updated from 1.3.4 to 1.3.5 without changing anything else and Swagger UI does not work anymore:

To Reproduce
Steps to reproduce the behavior:

• What version of spring-boot you are using? 2.2.6.RELEASE
• What modules and versions of springdoc-openapi are you using? before: implementation("org.springdoc:springdoc-openapi-ui:1.3.4") and 1.3.5 after
• What is the actual and the expected result using OpenAPI Description (yml or json)?
  Actual: missing. Expected: filled with at least something :)
• Provide with a sample code (HelloController) or Test that reproduces the problem
  Sorry, don´t have this, but I´ve seen an error that is maybe related:

com.fasterxml.jackson.databind.JsonMappingException: Null key for a Map not allowed in JSON (use a converting NullKeySerializer?) (through reference chain: io.swagger.v3.oas.models.OpenAPI["paths"]->io.swagger.v3.oas.models.Paths["/v1/devices"]->io.swagger.v3.oas.models.PathItem["get"]->io.swagger.v3.oas.models.Operation["responses"]->io.swagger.v3.oas.models.responses.ApiResponses["null"])

Expected behavior
The /v3/api-docs should be found again

Screenshots
see above

[bnasslahsen]

Can you do 2 things:

• test with v1.3.7

If its the same result. Please add then sample code to reproduce.

[lrozenblyum]

Might be duplicate of #630

[sticksen]

1.3.7 does not fix it.
Yes, #630 is the exact same problem. Example code is inside of #630.

[bnasslahsen]

#630 is fixed.
Can you please test with the latest Snapshot ?

[sticksen]

I´m happy to test as soon as 1.3.8 is available. Seems like the commit just didn´t make it into 1.3.7.
Fine for me, I can wait for 1.3.8. Thanks everybody!

[bnasslahsen]

Might be duplicate of #630.
Unable to reproduce with the sample code provided.

Can be valdated with v1.3.8 released today.
The ticket can be reopened, if the relevant information to reproduce the issue are provided.