Version Found: RLDRAM v1.0
Version Resolved: See (Xilinx Answer 58435)
A new DRC check has been added in Vivado 2015.3 on usage of the FIFO36E2 primitive.
It will cause critical warnings if an older MIG UltraScale RLDRAM3 IP is brought into Vivado 2015.3 without upgrading to the latest IP version.
The following CRITICAL WARNING might be seen:
To resolve the critical warning, upgrade the IP to RLDRAM3 v1.0 in Vivado 2015.3.
If you are unable to upgrade the IP, please contact Xilinx Technical Support through the Xilinx Service Portal: