LibGDX html:superDev task giving me an error

So I've been trying to run the libGDX command "gradlew html:superDev" for my project but it always gives me and error part way through the proccess:

> Task :html:beforeRun FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':html:beforeRun'.
> Could not resolve all files for configuration ':html:grettyRunnerJetty94'.
   > Could not find org.gretty:gretty-runner-jetty94:3.0.2.
     Searched in the following locations:
       - file:/C:/Users/Joachim/.m2/repository/org/gretty/gretty-runner-jetty94/3.0.2/gretty-runner-jetty94-3.0.2.pom
       - https://repo.maven.apache.org/maven2/org/gretty/gretty-runner-jetty94/3.0.2/gretty-runner-jetty94-3.0.2.pom
       - https://dl.google.com/dl/android/maven2/org/gretty/gretty-runner-jetty94/3.0.2/gretty-runner-jetty94-3.0.2.pom
       - https://oss.sonatype.org/content/repositories/snapshots/org/gretty/gretty-runner-jetty94/3.0.2/gretty-runner-jetty94-3.0.2.pom
       - https://oss.sonatype.org/content/repositories/releases/org/gretty/gretty-runner-jetty94/3.0.2/gretty-runner-jetty94-3.0.2.pom
     Required by:
         project :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

Deprecated Gradle features were used in this build, making it incompatible with Gradle 7.0.
Use '--warning-mode all' to show the individual deprecation warnings.
See https://docs.gradle.org/6.7.1/userguide/command_line_interface.html#sec:command_line_warnings

Any help in fixing this problem would be very much appreciated. Thanks!