I'm totally confused about the criteria for acceptance and/or rejection of dimensions of features that seem to be treated as "walls". I've had a T gauge tunnel portal accepted and printed successfully 18 times in white detail plastic. One of the details on this model is copings on top of brick columns. I've also had connecting walls accepted and printed in the same material. The walls have the very same coping details of exactly the same dimensions. All have printed exactly as expected them...with a good level of detail. Now I've had another item..wing walls..rejected because the coping detail of EXACTLY the same dimensions have been deemed to be walls and consequently at 0.45mm thick are too thin! I've emailed support querying why there is this inconsistency and all I got back was "Unfortunately we cannot print models which have been rejected." and very little else! No explanation why one model had a detail accepted and another model with the same detail was rejected. Nothing! Anyone else had a similar experience?? I'm now left with half-built items that have cost me a great deal of money that I may now have to throw away and redesign!!