Same problem here on one rig with 6x RX 470.
I've set working batch on AUTO, but the problem still occurs and shows 0 MH/s on Device 2 (card on the main slot.)
Also, have the same problem with other mining software so I guess I should better reinstall Win 10.
This makes me think it's something to do with onboard video.
Do either of you have onboard video enabled? Primary video should be set to PCIE and iGPU should be disabled in MB BIOS.
Might not be the problem, just a though.
I think it rather has something to do with the virtual memory. If few cards work but more do not its likely this.
Background: The Windows AMD drivers require the same amount of RAM on the mining system that they want to allocate on the GPU. So if a mining program tries to allocate 2Gb on the GPU the driver will also allocate 2G on the normal system RAM or virtual memory. This is only during start up and later the memory in RAM is freed. The work batch setting in lolMiner directly controls the GPU RAM usage of the miner. If it is set to AUTO the miner will try to use up to 60% of its available memory. So assume you have 8x RX580 with 8GB running the miner on AUTO setting, the OpenCL driver will try to allocate 8*8*60% = 38,4 GB system RAM. If the RAM is not enough lolMiner will swap to virtual memory (the Windows memory file). If that still is not enough not be able to create all the buffers (up to now there is no check) and the cards were the buffer could not be created for will run with 0 sol/s.