Have you tried to run a debug and a limited load.
In the data load editor, press the bug symbol top right ? The tick limited load, do like 10 lines.
See if it goes through, then check you data model, try to remove the synthetic keys.
If you are not sure where you are getting in the load, add the Trace function. Like
Trace 'Loading the table'
Trace 'Table loaded'
Hope this helps
So i did limited load.
I tried 100 rows and it looked like crashing again, so i stopped to prevent this and did the same with 10 rows max and it worked.
So i guess the Qlik Engine is overloaded by the 2mio rows and the big number of keys (i got 17 in total with 8 pure Data keys and the rest are syn keys of syn keys).
P.S.: mto I hope you can evaluate something with this informations and/or can give me some feedback on this behaviour