You're here because you can't run your jar.
Typically caused by a dependency that includes cryptographic information that will mark your jar as signed. To fix it you need to include some exclusion rules to remove those files.
The rule can be under uberJar or Jar or whatever does packaging in your gradle build.
uberJar {
exclude 'META-INF/*.RSA', 'META-INF/*.SF','META-INF/*.DSA'
}
An Android Application
packagingOptions {
exclude 'META-INF/LICENSE'
exclude 'META-INF/LICENSE.txt'
exclude 'META-INF/MSFTSIG.SF'
exclude 'META_INF/ECLIPSE_.SF'
exclude("META-INF/*.kotlin_module")
}