For those out there new to ReportServer, if you use Computed Columns, and if your database fields contain a space, you must use [] to enclose the field name, then go to the config list to add the function '[]' as 'eduardo' suggested in the above thread.
]]>you have to put the functions in the white list:
https://forum.reportserver.net/viewtopic.php?pid=3378
be careful to not to add "too much" to the whitelist in order to avoid sql injection. The whitelist is there in order to prevent sql injection and give you the control of which functions are allowed.
Regards,
Eduardo