Thanks for the detailed report, we will investigate. There are recurring issues with serial-over-USB which stem from the following limitation (in the linux kernel or in the serial-over-USB specifications, we are not sure):
- on the JeVois side, there is no way to know whether someone is listening on the host side
- but, if we send too much data and nobody is listening, we will eventually block as the buffers are full
So we have to find some logic for not blocking (which would completely halt the main loop on JeVois) without knowing whether someone is listening or not. That logic is in Serial.C in writeInternal() and indeed we have updated it recently which may have triggered your problem. The reason was that during large file transfers over that link (used by the Inventor to upload code, icons, etc to JeVois) we would eventually drop data which would completely break the transfer. We will try to update the logic so it both works for large file transfers and for your scenario. In the meantime, maybe try setpar drop true and see whether that has any effect?
the code is here, in writeInternal():