I agree with gr5, the first thing that came to my mind when you mentioned SketchUp is the file has non-manifold issues. Sketchup is not very good with making models that are solid. I would always suggest for you to run your models through a repair service just to ensure that the model is free of any errors. The best way is to upload it to https://www.MakePrintable.com and it’ll fix it automatically, there is also a SketchUp plugin that you can download from the site.
The model is probably not manifold despite the "shiny" claim. First try looking at the model in xray view. If you see any red then that's the problem spot - it means either a missing wall (a hole in the print) or an extra wall inside a solid. STL files model triangles - not solids so if you have a triangle on one side but no corresponding triangle on the other side - well - it's not a solid - so how do you 3d print something that isn't solid...
You can also play with the settings that try to auto fix this kind of thing. There are 4 settings you should try in cura 2.X "mesh fixes" group - try all of them - one at a time. You have to click one of the gears to enable these settings to be visible.
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