TLDR; Increase Virtual Memory (the Windows Page File Size) to at least 64,000 MB

The solution is to increase available virtual memory by increasing the page file size in Windows.

On Windows 10 set the page file size equal to your GPU memory size * number of GPUs. So for a rig running eight RX580 8GB GPUs, the page file size would be set to at least 64,000 MB (i.e, 64GB).

We recommend that you adhere the binary (base-2) memory size convention and round up to the nearest base-2 and thus use 65,536 MB (i.e, 2¹⁶ = 65,536).

Detailed Discussion: Virtual Memory and OpenCl Error 4

This is a Virtual Memory Problem that occurs on Windows-based mining rigs. If you’re using a 4GB ram stick in your rig, this error will come sooner rather than later. You wll soon realize that the conventional Windows 10 mining page file size of 16,384 MB (2¹⁴) is no longer adequate. As the Ethereum DAG file size increases on each epoch, an increase in operating system RAM is needed for the mining software. Hence, there are two solutions. Either install an extra 4GB stick of RAM to bring your rig to 8GB. Or, opt for the more cost effective solution and increase the paging file size.

What are DAG Files and Epochs n Ethereum Mining?

Every 30,000 blocks, a new piece of data [called a Directed Acyclic Graph (DAG)] is used for mining new blocks. Each new group of 30,000 blocks is known as an epoch. And epoch switch is when the next DAG is loaded.
– lungj via ethereum.stackexchange

What is Virtual Memory?

Virtual memory is a section of hard disk space that the Operating System (OS) uses as if it were RAM. It is typically referred to as the swap file (on Unix) or paging file (Windows). Most modern OSes automatically set a default swap/paging file size based on the amount of installed RAM.