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kotlinlang

The error message seems to point that you have two kotlinx-serialization on a classpath, likely bundled by some  transitive deps.

Either try to force one by pinning the version you would like to use at the end with `resolutionStrategy.force`

Another investigation lead would be for you to check if jettifier is still needed to be enabled. Support libraries are deprecated as of 2018 so hopefully 3 years was enough time to migrate from them.