Cannot 3D print prisms and ellipsoids


I get errors if I try to Printout3D[ ] or Export[ ] to an .stl file an object containing either an ellipsoid or prisms with any complexity. For example, neither:

testError = Graphics3D[{Tube[{{0, 0, 0}, {1, 1, 1}}, .1],    Ellipsoid[{1, 1, .5}, {1, 1, .1}]}] 

… nor

pos=20; top=.9; bottom=.1 testError=Graphics3D[   Table[Prism[{{0, 0, top}, {1.2 Cos@x, 1.2 Sin@x,top},  {1.2 Cos[x + 2 Pi/pos], 1.2 Sin[x + 2 Pi/pos], top}, {0, 0, bottom}, {1.2 Cos@x, 1.2 Sin@x,bottom}, {1.2 Cos[x + 2 Pi/pos], 1.2 Sin[x + 2 Pi/pos],bottom}}],  {x, 0, 2 \[Pi] - 2 \[Pi]/pos, 5 2 \[Pi]/pos}]] 

… produce the expected results with either Export["test.stl",testError] or Pintout3D[testError,"test.stl"]. What am I doing wrong? Using 12.1.