hansdc

as a Sketchup user I cannot recommend Solid Inspector (2) highly enough.

Thank you - installed the plugin and found MANY problems (slic3r fixed them quietly... well ist showed a 'number' of fixed) so I fixed my drawing - and it sliced fine! Printing it NOW thanks again

Not wanting to hijack the thread, But I do have a simple calibration piece, consisting of only straight lines (no curves) and it's solid, not hollow, that CURA doesn't seem to be able to slice.... I drew it in Sketchup, and exported as STL. When loading into CURA (14.12.x) the 'normal view' looks correct, but the layers are wrong - and printing the g-code resukts in the piece like the 'layers'. I changed the darwing several times - and no success... :( Sorry, no picture I can attach on this computer.

you need to go to the Applications directory using Finder, and 'open' cura with right-click. it then gives you the warning but you can selet open, and it will register the exception, in future it opens normally. Happened to me too ... This goes for all programs by ?unregistered developers? cheers H. oops - did not read the op's question properly ... :(