I need assistance with the Leave Allocations under the leaves app. 

I can create Leave Types, however when trying to set a leave allocation I get the following error(s):
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Odoo Server Error - Access Error
The requested operation cannot be completed due to security restrictions. Please contact your system administrator.

(Document type: res.users, Operation: read) 

From the server logs:
​odoo.models: The requested operation cannot be completed due to record rules: Document type: res.users, Operation: read, Records: 45,1, User: 45

I see that people recommend adding res.users to the user group or changing access rights / record rules. I have tried adding it at all possible locations and still receive the same error. 

Any help or assistance would be greatly appreciated.