in my code, I use many times,
and by changing the current folder this error appears for me.
well, in the second folder i have some java code to parse some data from the OANDA database and during this interaction/ some times i got timerfcn error.
i use pause(.1) after any cd() and then some errors are gone but still some time(it is vague for me when !) i faced with the error.
the bad point is when it faces with error entire of the cycle of timer stop.