[NTG-context] context --ctx=s-mod not working?

Hi list! I've tried context --ctx=s-mod with some files, e.g. t-annotation and I only get corrupted PDF files. Also, when I try with files such as syst-aux.mkiv, I get the following error after a L O T of warnings: \wait tex error > tex error on line 4554 in file syst-aux.mkiv: ? \wait ->\begingroup \read 16 to \wait \endgroup \installsystemnamespace ...??#1\endcsname \writestatus \m!system {duplicate system namespace '#1'}\wait \else \global \advance \c_syst_helpers_n_of_names... l.4554 \installsystemnamespace{extraevery} <empty file> Is it a bug or am I missing some additional settings? Thank you very much. Jairo :)