Hi Ahmed!
Bingo 
After trying many things it suddently came to mind that maybe the final parts of the spring might cause the non-convergence issue (maybe they are too thin to be meshed properly for this non-linear simulation?). I’ve updated the spring (cut-off the final bits of the spring ends) after which I rerun the analysis and this time it converged!
Maybe it’s still possible to succesfully run a simulation with the original spring (with thin ends), but I think I have to further refine these ends. Do you think this reasoning makes sense?
Cheers