Looks like Callisto in the Ethash-lowmemory pool has a 3.41GB DAG size, which could cause an error if your GPU only has 3GB of VRAM. You could use the c= parameter to static mine a coin with a lower DAG size. The DAG sizes can be checked on our Status page. Steven thank you for this reply, I wasn't...

Has anything changed with ETHASH-LowMemory? I have a couple of older systems that normally run ETHash-LowMemory but for the last couple of days they have not been able to connect. When I start the miner I get an immediate disconnect, in the mining dashboard I get the error "The worker does not ...