The homey Mike pointed this one out
If you ever run into the following log entry:
Error 512: Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <=, >, >= or when the subquery is used an expression.
You might want to check if you have recently setup a CPU Alert condition.
We aren’t sure why or how to remedy this, but at the least it will clear up the error and your logs.