File Path Issue on Windows with OAS 3.1 - Illegal character in opaque part at index

[gexclaude]

We encountered the issue here, when using OpenAPITools Generator (Maven Plugin) after we switched from OAS 3.0.3 to 3.1.0:
OpenAPITools/openapi-generator#18161

As the Issue on OpenAPITools indicates, the error might be in the swagger-parser. At least we see in the stacktrace, that the error happens there. Is this a known issue?

Our full stack trace.

java.net.URISyntaxException: Illegal character in opaque part at index 2: C:\repos\my-project\api/src/main/resources/oas31-api.yaml
at java.net.URI$Parser.fail (URI.java:2995)
at java.net.URI$Parser.checkChars (URI.java:3166)
at java.net.URI$Parser.parse (URI.java:3202)
at java.net.URI.<init> (URI.java:645)
at io.swagger.v3.parser.reference.ReferenceUtils.resolve (ReferenceUtils.java:29)
at io.swagger.v3.parser.reference.ReferenceVisitor.resolveSchemaRef (ReferenceVisitor.java:227)
at io.swagger.v3.parser.reference.ReferenceVisitor.visitSchema (ReferenceVisitor.java:141)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverseSchema (OpenAPI31Traverser.java:790)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverseMediaType (OpenAPI31Traverser.java:603)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverseMap (OpenAPI31Traverser.java:933)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverseRequestBody (OpenAPI31Traverser.java:346)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverseOperation (OpenAPI31Traverser.java:229)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traversePathItem (OpenAPI31Traverser.java:424)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverseMap (OpenAPI31Traverser.java:933)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traversePaths (OpenAPI31Traverser.java:197)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverseOpenApi (OpenAPI31Traverser.java:124)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverse (OpenAPI31Traverser.java:65)
at io.swagger.v3.parser.reference.OpenAPIDereferencer31.dereference (OpenAPIDereferencer31.java:74)
at io.swagger.v3.parser.OpenAPIV3Parser.resolve (OpenAPIV3Parser.java:227)
at io.swagger.v3.parser.OpenAPIV3Parser.readContents (OpenAPIV3Parser.java:183)
at io.swagger.v3.parser.OpenAPIV3Parser.readLocation (OpenAPIV3Parser.java:97)
at io.swagger.parser.OpenAPIParser.readLocation (OpenAPIParser.java:16)
at org.openapitools.codegen.config.CodegenConfigurator.toContext (CodegenConfigurator.java:686)
at org.openapitools.codegen.config.CodegenConfigurator.toClientOptInput (CodegenConfigurator.java:744)
at org.openapitools.codegen.plugin.CodeGenMojo.execute (CodeGenMojo.java:940)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:126)
at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:328)
at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:316)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:212)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:174)
at org.apache.maven.lifecycle.internal.MojoExecutor.access$000 (MojoExecutor.java:75)
at org.apache.maven.lifecycle.internal.MojoExecutor$1.run (MojoExecutor.java:162)
at org.apache.maven.plugin.DefaultMojosExecutionStrategy.execute (DefaultMojosExecutionStrategy.java:39)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:159)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:105)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:73)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:53)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:118)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:261)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:173)
at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:101)
at org.apache.maven.cli.MavenCli.execute (MavenCli.java:903)
at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:280)
at org.apache.maven.cli.MavenCli.main (MavenCli.java:203)
at jdk.internal.reflect.DirectMethodHandleAccessor.invoke (DirectMethodHandleAccessor.java:103)
at java.lang.reflect.Method.invoke (Method.java:580)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:255)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:201)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:361)
at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:314)
at org.codehaus.classworlds.Launcher.main (Launcher.java:41)

[DaleGardner]

I'm experiencing this same issue with the file path having the wrong slashes