Error4 reports
Fix MiniflareCoreError
in Cloudflare Workers
✅ Solution
MiniflareCoreError often arises from conflicting or improperly configured bindings, especially when using browser bindings or multiple workers in the same environment. Ensure all bindings are correctly defined in your wrangler.toml or CLI arguments and that there are no conflicting binding types (e.g., attempting to use browser bindings with module workers simultaneously). If using multiple workers, verify each worker has unique binding names to avoid overlapping modules. Finally, double-check that the referenced modules in your bindings are correctly present and resolvable in your project.
Related Issues
Real GitHub issues where developers encountered this error:
Timeline
First reported:Nov 25, 2025
Last reported:Dec 19, 2025
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