>>The SYS(3) function returns the number of miliseconds since midnight as a string.

? INT(Seconds()*1000), Sys(3)

Whar error do you get?
>>
>I am getting "Invalid path or filename", which is not a surprise according to your explanatation. What surprises me, that this code was 5 or more years in production and we never met this problem before. It is weird, if it always behaved this way, the error should have been discovered years ago...
>
>I vaguely remember, that I've discovered the same problem in my other colleague's code and we fixed it there. But why this piece of code, which was executed every day 1000s of times, was never failing before - it is a mystery for me...
>
>Anyway, I guess, I have to write a letter to my former manager (I am also thinking, should I include my colleague, who is the owner of these classes, in this memo?).

No, my info doesn't explain your error. You can create file with such name. Try

lcTemp = SYS(3)
CREATE TABLE (lcTemp) FREE (CLASS C(40))

Most likely, the path stored in gctemppath is either incorrect or doesn't have ending "\".