When returning 1000 from BrokerCommand for GET_MAXTICKS, I can get 900 ticks from BrokerHistory2 in one call, but it crashes when trying to get 1000. Clearly the tick buffer has not been sized with 1000 or something unexplained in the manual is going on...
FYI I counted the number of ticks it could process to guess the tick buffer size and I got different results before crashing for different call to Download like 943 or 956.