Feature flag __VUE_PROD_HYDRATION_MISMATCH_DETAILS__ is not explicitly defined. You are running the esm-bundler build of Vue, which expects these compile-time feature flags to be globally injected via the bundler config in order to get better tree-shaking in the production bundle.

For more details, see https://link.vuejs.org/feature-flags. runtime-core.esm-bundler.js:5227