This scan happen when the button part on the switch is `dirty` the carbon inside the touch switch accumulates, its a full strip down and cleaning the circuit board part of the switch with a non solvent alcohol based cleaner.
Make sure you're using the correct power adapter or that the one you have is not malfunctioning. I've experienced Roland/Boss equipment blinking (and restarting over and over) when they are not receiving enough power. Sometimes even the resistance caused by too long of an extension cord can cause this to happen.
Use 1/4" plug cables or XLR-1/4" cables with the fx loop, depending on the type of connector of your mixer. Don't use batteries, they don't last. Use a type 2 (for noise reduction) 9V wall outlet adapter.
Information is minimal. When does it come up with this and what is the exact message. Seems like the output for expression pedal/SW is corrupt. Expression pedal not good or the output?