We have just been made aware of an issue when trying to add a new add-on into SAP Dashboards (Xcelsius) version 4.2 SP4
Symptom: When you try and add the add-on through "Manage Addons" you see the error "Add-On Cannot Be Installed". Any addons you had installed prior to upgrading will continue to function as normal.
Cause:
This has been reported to SAP on Note # 2475742 and a fix will be implemented in 4.2 SP4 Fix Pack 1.
Work Around:
It is possible to get around this issue whilst we are waiting for FP1. If you put the addon XLX into the root of the Xcelsius install folder (eg C:\Program Files (x86)\SAP BusinessObjects\Xcelsius 4.0) then when you go to Manage Addons you will be able to add the addon now.