error'1004': We couldn't copy this sheet

Hello @Sandy, 

Thank you for posting your valuable question on the Microsoft Q&A forum. 

We want to ensure our responses are helpful and complete. However, this particular issue involves custom development or environment-specific behavior, which falls outside the scope of this forum. Our focus here is on Excel’s built-in functions and features.

However, based on my research, here’s what I’ve found so far: 

From the details you shared, the error 1004: We couldn’t copy this sheet seems related to a locale or language mismatch, triggered by: 

• Sheet names in Chinese characters that may not be handled correctly when the system locale is English. 
• Possible dependencies in the workbook or VBA code that assume Chinese-language regional settings. 

When Excel tries to process a copy operation under English locale, it likely fails to properly interpret sheet names or internal metadata, causing the copy to abort and throw the error. This behavior is reversed when the locale matches the original (Chinese) environment. 

What you can try: 

• Rename sheets to English before changing system language. 
• Check VBA code for hardcoded Chinese sheet names and replace them with English or use index-based references. 
• If the issue persists, recreate the workbook under English settings and copy data/macro logic into it. 

If that is not the exact issue you're facing, we recommend re-posting on Stack Overflow, where developers actively discuss these topics, especially those involving VBA or Visual Basic. Be sure to include details such as: 

• Your code snippet (if macros are involved) 
• Excel version 
• Any language or regional settings that might affect the workbook 

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We’re truly sorry for any inconvenience this may cause. We understand how frustrating it can be when you’re looking for a solution and we’re unable to provide the level of support you need. Our goal is to ensure you receive accurate and helpful guidance, and in this case, the best way to achieve that is by directing you to a resource better suited for development-related questions. 

Thank you for reaching out! Have a nice day and stay healthy! 

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