Failed to decrypt object will be covered by this sap note:
https://support.wdf.sap.corp/sap/support/notes/1754247
Without getting into the issues one by one, I would HIGHLY recommend looking at 4.1 SP3 which has a lot of LCM stability and performance improvements.
Also there is a large collection of KB articles that you can cross reference here:
BI4 Upgrade and Promotion Management KBAs - Business Intelligence (BusinessObjects) - SCN Wiki