This is what my start.bat looks like:
set GPU_FORCE_64BIT_PTR=0
set GPU_MAX_HEAP_SIZE=100
set GPU_USE_SYNC_OBJECTS=1
set GPU_MAX_ALLOC_PERCENT=100
set GPU_SINGLE_ALLOC_PERCENT=100
EthDcrMiner64.exe -epool eth-eu1.nanopool.org:9999 -ewal 0x*****************/rig021/***@***.com -epsw x -mode 1 -ftime 10 -cclock 1140 -mclock 2090,2090,2080,2080,2080,2060,2060,2060,2060,2060,2060,2050 -powlim 50 -cvddc 900 -di 012345678
Claymore v12 running on Win10 build 1809 AMD driver 19.4.1. The problem may have started when I moved from build 1709 to 1803 or 1809. Or it may be when the DAG grew above a certain size.