[NTG-context] Undefined controle sequence with usemodule[vim]

Hello everyone, When I use t-vim module, I get this error message: <error msg> system > tex > error on line 15 in file vim.tex: Undefined control sequence ... for example with this code: <code> \usemodule[vim] \definevimtyping[python][syntax=python, escape=on] \starttext \startpython # Returns \m{\sum_{i=1}^{n}i} def sum_upto(n) r = range(1, n+1) return sum(r) \stoppython \stoptext </code> But as you can see, there is no line 15 in this file ! Anyway, I can just ignore the error and get the output, but that’s not good. I attached the log file.