Policy
File Block includes external link files
This setting determines whether Trust Center settings for blocking load of potentially unsecure workbooks applies to those accessed by external links. If you enable this policy setting, external links to workbooks that are blocked by File Block settings in Trust Center will not refresh. Attempts to create new links or refresh data from blocked workbooks may result in errors. If you disable this policy setting, attempts to access external links data will not be subject to File Block settings in Trust Center.
5cb948a5dc14 L_ExcelFileBlockExternalLinks Registry
Copy registry mappings
HKCU\software\policies\microsoft\office\16.0\excel\security\fileblock\fileblockexternallinks (enabled) = 1
HKCU\software\policies\microsoft\office\16.0\excel\security\fileblock\fileblockexternallinks (disabled) = 0 Policy notes
This setting determines whether Trust Center settings for blocking load of potentially unsecure workbooks applies to those accessed by external links. If you enable this policy setting, external links to workbooks that are blocked by File Block settings in Trust Center will not refresh. Attempts to create new links or refresh data from blocked workbooks may result in errors. If you disable this policy setting, attempts to access external links data will not be subject to File Block settings in Trust Center.