Upvote:1
As far as I know, one cannot have simultaneously two valid Schengen visas. Any previous valid visas need to be revoked first.
Though it is rarely stated in explicit terms, if you visit any relevant embassy you will quickly find it out. I did a quick search and found several links. Take for example, Embassy of Norway says:
A person cannot have two valid Schengen visas at the same time.
On a related note, they say:
Can I apply both for C-visa and for a residence permit?
No. There cannot be two applications at the same time for the same person. You will have to choose.