It seems like you're encountering an error message: "err err.param". This is a bit vague, but I can help you troubleshoot it. Could you please provide more context or details about what you're trying to do and what exactly is going wrong?
For example:
- Are you working with a web application?
- Are you using a specific programming language or framework (e.g., Python, JavaScript, React, etc.)?
- Are you trying to pass parameters to a function or API call?
If you can share more information, I'd be happy to help you resolve the issue.