Hi,
Thanks for posting in Microsoft MECM Q&A forum.
The error code 0xC1900204 means "The migration choice selected is not available (ex: Enterprise to Home, the wrong SKU or architecture)". Is the problematic client OEM computer? Please also make sure the upgrade is not LTSC. In-place upgrade from Windows 8.1, or Windows 10 semi-annual channel to Windows 10 LTSC is not supported.
During my research, I found this may be language issue or license issue (mismatch of product key). Please check the registry key 'HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Nls\Language\InstallLanguage on the client to see if the language matchs you operating system. And also check if the product key is correct.
Similar error described here for your reference:
Windows 10 Inplace Issues 0xC1900204 - Configuration Manager
Windows Setup failed with hexadecimal exit code 0xC1900204
Here are some official articles for your reference:
Windows 10 upgrade paths
Windows 10 Pre-Upgrade Validation using SETUP.EXE
Hope it helps. Thanks for your time.
Best regards,
Simon
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