Good to see that you inputted your file as a STEP file which has more compatibility with the meshing algorithms of SIMSCALE. But, It seems you have a problem with the meshing. This is because you have multiple individual solids in your model. Try to merge the solids of your model into single solid and make it as simple as possible. To know how to make the multiple solids into single solids you can have a look at this link.
Making multiple solids into single solids will help to reduce your efforts in defining contacts between individual solids.
Also looking at your Mesh properties, you are using Very fine mesh with only 4 computing cores. This leads to lack of memory. So instead try to have a coarse mesh in the initial run with 4 computing cores. You can have a fine mesh with more computing cores in the later run.
Hope this helps. If you have any further queries, feel free to contact. Happy Simulating!
-Madan (@Madan_Mohan )