id summary reporter owner description type status priority milestone component version resolution keywords cc 29 Assertion failed gfxcore.cc line 2232 Duncan Collis Olly Betts "On clicking 'show passage tubes' for the attached 3d file I get the following error message (which, incidentally, I can't copy + paste, which is unhelpful) Microsoft Visual C++ Runtime Library Assertion failed! Program: C:\Program Files\Survex\aven.exe File: gfxcore.cc Line: 2232 Expression: z >=0.0" defect closed minor 1.2.2 aven 1.2.1 fixed aven tubes assertion gfxcore