gradlew check does not pass on Windows

[7ep]

Several unit tests fail when running this on Windows.
Used the gradle wrapper
Java: 11.0.5 (openjdk)
Windows 10
Running from the "cmd" program on Windows:
C:\Users\byron\dev\http4k-by-example>git clean -fxd
Removing .gradle/
Removing build/

C:\Users\byron\dev\http4k-by-example>gradlew check jacocotestreport

Task :test

functional.ManageUsersTest > add user(Approver) FAILED
java.nio.file.InvalidPathException at ManageUsersTest.kt:29

functional.ManageUsersTest > add user then delete them(Approver) FAILED
java.nio.file.InvalidPathException at ManageUsersTest.kt:37

functional.ManageUsersTest > manage users requires login via oauth(Approver) FAILED
java.nio.file.InvalidPathException at ManageUsersTest.kt:22

functional.WebTest > homepage(Approver) FAILED
java.nio.file.InvalidPathException at WebTest.kt:21

functional.WebTest > serves static content(Approver) FAILED
java.nio.file.InvalidPathException at WebTest.kt:26

40 tests completed, 5 failed, 6 skipped

Task :test FAILED

FAILURE: Build failed with an exception.

• What went wrong:
  Execution failed for task ':test'.

There were failing tests. See the report at: file:///C:/Users/byron/dev/http4k-by-example/build/reports/tests/test/index.html

• Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

• Get more help at https://help.gradle.org

BUILD FAILED in 13s
5 actionable tasks: 5 executed

C:\Users\byron\dev\http4k-by-example>