If you haven’t opened it up yet to see what you are up against here’s a picture. From what I understand, the parts that fail are the clear plastic pieces (AKA Light Pipes) that hold the PC board in place over the switch actuators. As you can see, the medal part of the switch that you step on is actually only an actuator that pushes on a tactile switch which is attached to the PC board, those plastic pieces hold the PC board and switches inline with the actuators, this is why when one switch fails, one or two of the switches next to it on the same row usually fail also. At some point Line 6 redesigned something to fix this but as far as I can tell the basic design is still the same so I would assume that they simply improved the plastic pieces somehow. You might try to call Line 6 to see if they will send you the parts, otherwise you’ll have to try and find an authorized service center that is willing to sell you the parts.

BTW, early on there were reports that Line 6 applied hot glue to try and help hold this all together, since they don’t do that anymore I think it’s safe to say that it doesn’t work.