Hi Hokyung,
I also tried with mouse input, and the error persists so it does not seem to be only an Eyelink problem.
I guess that’s good, because I have not been able to find any issues in the EyeLink plugin code that would cause it to output NaN or other non-finite eye position values.
I see many many warning messages for many (but not all) variables in the form of: “Invalid persistent value for variable “x””. I don’t recall this happening before I began to see the crash, though I might have just missed it then. I wonder if this is related at all.
This indicates that the versions of MWClient and MWServer that you’re using are mismatched. Specifically, MWServer must be version 0.11 or earlier, and MWClient must be 0.12 or later.
As I tried to say previously, mixing versions this way is never OK. You must use the same version for both MWServer and MWClient, even when they’re running on separate machines.
Chris