Version Found: v1.1 (Rev1)
Version Resolved and other Known Issues: See (Xilinx Answer 61898)
In Vivado 2015.2, the AXI Bridge for PCI Express Gen3 core configuration GUI has the 'AXI Master/Slave Outstanding Write/Read Transactions' option grayed out and fixed to '8'.
Note: "Version Found" refers to the version where the problem was first discovered.
The problem may also exist in earlier versions, but no specific testing has been performed to verify earlier versions.
06/24/2015 - Initial Release