I had the same error and WS-C3850-48XS switch would not boot. Booting...(use DDR clock 667 MHz)*** Address Error (Load/Fetch) Exception ***PC = 0x00000000 00000000SP = 0xffffffff 800594e4Cause Reg = 0x00000000 40008010, Status Reg = 0x00000000 50400...