openapi-generator-maven-plugin:5.0.1:generate Unable to read location `src/main/openapi/project.yaml`

[INFO]
[INFO] --- openapi-generator-maven-plugin:5.0.1:generate (default) @ foo ---
[WARN] Exception while reading:
io.swagger.v3.parser.exception.ReadContentException: Unable to read location `src/main/openapi/foo.yaml`
        at io.swagger.v3.parser.OpenAPIV3Parser.readContentFromLocation(OpenAPIV3Parser.java:238)
        at io.swagger.v3.parser.OpenAPIV3Parser.readLocation(OpenAPIV3Parser.java:87)
        at io.swagger.parser.OpenAPIParser.readLocation(OpenAPIParser.java:16)
        at org.openapitools.codegen.config.CodegenConfigurator.toContext(CodegenConfigurator.java:518)
        at org.openapitools.codegen.config.CodegenConfigurator.toClientOptInput(CodegenConfigurator.java:568)
        at org.openapitools.codegen.plugin.CodeGenMojo.execute(CodeGenMojo.java:717)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:137)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:210)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:156)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:148)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)
        at org.mvndaemon.mvnd.builder.SmartBuilderImpl.buildProject(SmartBuilderImpl.java:178)
        at org.mvndaemon.mvnd.builder.SmartBuilderImpl$ProjectBuildTask.run(SmartBuilderImpl.java:198)
        at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
        at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.RuntimeException: Could not find src/main/openapi/foo.yaml on the classpath
        at io.swagger.v3.parser.util.ClasspathHelper.loadFileFromClasspath(ClasspathHelper.java:31)
        at io.swagger.v3.parser.OpenAPIV3Parser.readContentFromLocation(OpenAPIV3Parser.java:229)
        ... 17 common frames omitted
[ERROR] failed to read resource listing
java.lang.RuntimeException: Could not find src/main/openapi/foo.yaml on the classpath
        at io.swagger.parser.util.ClasspathHelper.loadFileFromClasspath(ClasspathHelper.java:31)
        at io.swagger.parser.SwaggerCompatConverter.readResourceListing(SwaggerCompatConverter.java:207)
        at io.swagger.parser.SwaggerCompatConverter.read(SwaggerCompatConverter.java:123)
        at io.swagger.parser.SwaggerCompatConverter.readWithInfo(SwaggerCompatConverter.java:94)
        at io.swagger.parser.SwaggerParser.readWithInfo(SwaggerParser.java:44)
        at io.swagger.v3.parser.converter.SwaggerConverter.readLocation(SwaggerConverter.java:89)
        at io.swagger.parser.OpenAPIParser.readLocation(OpenAPIParser.java:16)
        at org.openapitools.codegen.config.CodegenConfigurator.toContext(CodegenConfigurator.java:518)
        at org.openapitools.codegen.config.CodegenConfigurator.toClientOptInput(CodegenConfigurator.java:568)
        at org.openapitools.codegen.plugin.CodeGenMojo.execute(CodeGenMojo.java:717)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:137)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:210)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:156)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:148)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)
        at org.mvndaemon.mvnd.builder.SmartBuilderImpl.buildProject(SmartBuilderImpl.java:178)
        at org.mvndaemon.mvnd.builder.SmartBuilderImpl$ProjectBuildTask.run(SmartBuilderImpl.java:198)
        at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
        at java.base/java.lang.Thread.run(Thread.java:834)
[INFO] Generating with dryRun=false
[WARN] Output directory does not exist, or is inaccessible. No file (.openapi-generator-ignore) will be evaluated.
[WARN] Z:\Workspaces\hpf-ghost-observer\ROOT\src\main\openapi\foo.yaml [0:0]: unexpected error in Open-API generation
java.lang.RuntimeException: missing OpenAPI input!
        at org.openapitools.codegen.DefaultGenerator.generate(DefaultGenerator.java:837)
        at org.openapitools.codegen.plugin.CodeGenMojo.execute(CodeGenMojo.java:739)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:137)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:210)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:156)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:148)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)
        at org.mvndaemon.mvnd.builder.SmartBuilderImpl.buildProject(SmartBuilderImpl.java:178)
        at org.mvndaemon.mvnd.builder.SmartBuilderImpl$ProjectBuildTask.run(SmartBuilderImpl.java:198)
        at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
        at java.base/java.lang.Thread.run(Thread.java:834)
[ERROR]
java.lang.RuntimeException: missing OpenAPI input!
        at org.openapitools.codegen.DefaultGenerator.generate(DefaultGenerator.java:837)
        at org.openapitools.codegen.plugin.CodeGenMojo.execute(CodeGenMojo.java:739)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:137)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:210)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:156)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:148)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)
        at org.mvndaemon.mvnd.builder.SmartBuilderImpl.buildProject(SmartBuilderImpl.java:178)
        at org.mvndaemon.mvnd.builder.SmartBuilderImpl$ProjectBuildTask.run(SmartBuilderImpl.java:198)
        at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
        at java.base/java.lang.Thread.run(Thread.java:834)
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------

mvnd native client 0.4.1-windows-amd64 (2336bde9192e9d0ccc3a5d2bf13abc9f295e21a7)
Terminal: org.jline.terminal.impl.PosixSysTerminal with pty org.jline.terminal.impl.ExecPty
Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f)
Maven home: C:\Users\SteffenFlemming\.sdkman\candidates\mvnd\current\mvn
Java version: 11.0.9.1, vendor: AdoptOpenJDK, runtime: C:\Users\SteffenFlemming\.sdkman\candidates\java\current
Default locale: en, platform encoding: Cp1252
OS name: "windows 10", version: "10.0", arch: "amd64", family: "windows"

while with maven wrapper it works

[INFO]
[INFO] --- openapi-generator-maven-plugin:5.0.1:generate (default) @ foo ---
[INFO] Generating with dryRun=false
[WARNING] Output directory does not exist, or is inaccessible. No file (.openapi-generator-ignore) will be evaluated.
[INFO] OpenAPI Generator: java (client)
[INFO] Generator 'java' is considered stable.
[INFO] Environment variable JAVA_POST_PROCESS_FILE not defined so the Java code may not be properly formatted. To define it, try 'export JAVA_POST_PROCESS_FILE="/usr/local/bin/clang-format -i"' (Linux/Mac)
[INFO] NOTE: To enable file post-processing, 'enablePostProcessFile' must be set to `true` (--enable-post-process-file for CLI).
[INFO] Invoker Package Name, originally not set, is now derived from api package name: de.openapi
[INFO] Processing operation getProjects
[INFO] Processing operation getProjectDetails

Apache Maven 3.8.1 (05c21c65bdfed0f71a2f2ada8b84da59348c4c5d)
Maven home: C:\Users\SteffenFlemming\.m2\wrapper\dists\apache-maven-3.8.1-bin\2l5mhf2pq2clrde7f7qp1rdt5m\apache-maven-3.8.1
Java version: 11.0.9.1, vendor: AdoptOpenJDK, runtime: C:\Users\SteffenFlemming\.sdkman\candidates\java\current
Default locale: de_DE, platform encoding: Cp1252
OS name: "windows 10", version: "10.0", arch: "amd64", family: "windows"