Third-party antivirus software can conflict with Office applications, causing Excel to freeze, fail to start, or stop responding after startup. Some antivirus software does not recognize macros or add-ins correctly and blocks them. In many cases, a warning message is not even displayed. Check the scan logof your antivirus software to see whether it blocked Excel or an add-in. Even if you can’t find anything in the log, you should try to start Excel with the antivirus software deactivated. If that solves the problem, it usually means that your antivirus software was the culprit.
Some antivirus software includes add-ins that are installed in Excel to provide additional security features. However, these add-ins often conflict with add-ins from other vendors. In this case, consider which add-in is more important.
Go to the settings of your antivirus software and try to exclude Excel along with all the add-ins you want to use. You are unlikely to have any problems starting Excel and other Microsoft applications if you use the built-in Microsoft Defender Antivirus software in Windows 10 instead of third-party anti-malware programs.