Server 2012 Mapped drive access via IE

[nathan]

Hi,

 

We're running a server 2012 r2 and using remote desktop services. When users log in they get there own mapped drive. The users can access these mapped drives fine which means the permissions are all correct. But when they use Internet Explorer and a website wants the to upload a csv file they cannot access the mapped drive - the error states a permissions issue.

 

Is Internet Explorer running in another security context? If so how do i get around it?