Describe the bug

Steps to reproduce
- User alice creates a private link to some of her folders (not shared with anybody) and discloses the link to bob.
- User bob tries to access the link. An error appears that claims, that it is shared, but needs "syncing". This is wrong. BAD
- Same error appears when the link is malformed.
Expected behavior
A clear and concise error message should say:
- you don't have access.
- the link is malformed.
- ...
Actual behavior
The user is mislead to actions that don't help.