If an export file is opened with EXCEL, an error/warning appears, before the file opens:
The file format and extension of 'export.xls' don't mathc. The file could be corrupted or unsafe. Unless you trust its source, don't open it. Do you want to open it anyway?
If you open the export.xls file with notepad++, you can see, that this is a .xml file, which is just named .xls by SDM.
If SDM would name it .xml, then Excel would open this file without any error/warning. This is not performed by default, however, as on most environments .xml files default to opening in a web browser, rather than Excel.
Release : 17.3
Component : SERVICE DESK BUSINESS OBJECTS
While this isn't able to go into the product as a permanent change, due to the side-effects with xml files not defaulting to Excel in most instances, this is something be changed for any environment.
The following MDB update query will set the export to use the .xml extension:
update usp_exlist_format set file_extension = 'xml' where sym = 'Excel file'
And to change it back
update usp_exlist_format set file_extension = 'xls' where sym = 'Excel file'
There's also a tenant column in that table, if you only wish to enable this for particular tenants.
Alternatively, the warning can be disabled in the client machine's registry:
Open reg edit, navigate to HKEY_CURRENT_USER\Software\Microsoft\Office\14\Excel\Security
Create a DWord with name ExtensionHardening and set the value to 0.