Scenario:
This problem is known to happen with One-drive for Business ;
Users could report they are unable to share and when trying to contact a list of 365 contacts inside onedrive or any 365 app the list comes blank
You would encounter that users are not able to share or search people on the share send lick ( 2nd picture below) .
Here is the fix:
1.Open Internet Explorer / Options / Advanced
2.Untick “Do not save encrypted files to disk “
After this change you should be able to share.
Also you can implement this via GPO as shown:
sevenitblog.com 