springfox: Unable to scan documentation context default java.lang.NullPointerException: null

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• What version of the library are you using? Is it the latest version? The latest released version is 3.0.0-SNAPSHOT

What kind of issue is this?

• Question. Is this a question about how to do a certain thing? no it is not.
• Bug report. If you’ve found a bug, spend the time to write a failing test. Bugs with tests or steps to reproduce get fixed faster. Here’s an example: https://gist.github.com/swankjesse/6608b4713ad80988cdc9
  • spring xml/java config that is relevant
  • springfox specific configuration if it makes sense
  • include any output you’ve received; logs, json snippets etc.; and what the expected output should be I have a production ready Spring Boot project which until last week works fine(swagger part). And after one deploy yesterday, suddenly we cannot access the swagger page. The url was https://our-api-root/swagger-ui.html.

I see this exception when I launch the project locally(the bootrun works but with this error):

Unable to scan documentation context default java.lang.NullPointerException: null
	at springfox.documentation.spi.schema.contexts.ModelContext.<init>(ModelContext.java:89)
	at springfox.documentation.spi.schema.contexts.ModelContext.fromParent(ModelContext.java:264)
	at springfox.documentation.schema.ModelReferenceProvider.typeName(ModelReferenceProvider.java:108)
	at springfox.documentation.schema.ModelReferenceProvider.modelReference(ModelReferenceProvider.java:71)
	at springfox.documentation.schema.ModelReferenceProvider.apply(ModelReferenceProvider.java:61)
	at springfox.documentation.schema.ModelReferenceProvider.apply(ModelReferenceProvider.java:39)
	at springfox.documentation.schema.ModelProperty.updateModelRef(ModelProperty.java:128)
	at springfox.documentation.spring.web.scanners.ApiModelReader.findSameModels(ApiModelReader.java:322)
	at springfox.documentation.spring.web.scanners.ApiModelReader.mergeModelBranch(ApiModelReader.java:245)
	at springfox.documentation.spring.web.scanners.ApiModelReader.lambda$mergeModelBranch$8(ApiModelReader.java:192)
	at java.base/java.util.Optional.orElseGet(Optional.java:369)
	at springfox.documentation.spring.web.scanners.ApiModelReader.mergeModelBranch(ApiModelReader.java:192)
	at springfox.documentation.spring.web.scanners.ApiModelReader.lambda$read$4(ApiModelReader.java:145)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
	at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1654)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
	at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
	at springfox.documentation.spring.web.scanners.ApiModelReader.read(ApiModelReader.java:144)
	at springfox.documentation.spring.web.scanners.ApiListingScanner.scan(ApiListingScanner.java:144)
	at springfox.documentation.spring.web.scanners.ApiDocumentationScanner.scan(ApiDocumentationScanner.java:69)
	at springfox.documentation.spring.web.plugins.AbstractDocumentationPluginsBootstrapper.scanDocumentation(AbstractDocumentationPluginsBootstrapper.java:97)
	at springfox.documentation.spring.web.plugins.AbstractDocumentationPluginsBootstrapper.bootstrapDocumentationPlugins(AbstractDocumentationPluginsBootstrapper.java:83)
	at springfox.documentation.spring.web.plugins.SpringIntegrationDocumentationPluginsBootstrapper.contextRefreshedEventExecute(SpringIntegrationDocumentationPluginsBootstrapper.java:81)
	at org.springframework.context.event.ApplicationListenerMethodAdapter.doInvoke(ApplicationListenerMethodAdapter.java:305) [4 skipped]
	at org.springframework.context.event.ApplicationListenerMethodAdapter.processEvent(ApplicationListenerMethodAdapter.java:190)
	at org.springframework.context.event.ApplicationListenerMethodAdapter.onApplicationEvent(ApplicationListenerMethodAdapter.java:153)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:403)
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:360)
	at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:897)
	at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.finishRefresh(ReactiveWebServerApplicationContext.java:129)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:553)
	at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.refresh(ReactiveWebServerApplicationContext.java:66)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:315)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215)
	at eu.vptech.checkoutexp.checkout.CheckoutApplication.main(CheckoutApplication.java:11)

- [ ] if you have a repo that demonstrates the issue for bonus points! See [this example](https://github.com/springfox/springfox/issues/494) 

Tried to reproduce it with a simple demo project but failed.

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