Warning while saving opportunity in OpenERP
Hi these is due to the access right problem .So you give the proper access right to your user(for creating the oppurtunity)
After creating an opportunity, when I click on save, it gives me this warning for some users: 

"Operation prohibited by access rules, or performed on an already deleted document (Operation: read, Document type: User Modification)."

What's causing this problem?
Update: I have created a new user of admin type and I added these groups:
Sales/User,Sales/User All Leads,Survey/User,Tools/User. It gives me a warning while creating an opportunity.
I added the following groups to the new user and it's working fine: Employee, PartnerManager, Marketing/User, Accounting/Accountant, Accounting/Invoice, Accounting/Manager, Administration/Access Rights, Human Resource/Manager, Human Resource/User, Knowledge/User, Marketing/Manager, Project/Manager, Sales/Manager, Tools/Manager, trimax/AdminMeeting, Trimax/‌​SalesExecutive, Trimax/Vertical, Trimax/SalesHead, Trimax/SalesManager, Useability/An‌alyticAccounting, Useability/Extended, View, Useability/MultiCompanies, Useability/No One, Useability/Product Uos View, Useability/Product Variant, Warehouse/Manager, Warehouse/User, Tools/User, Administration/Configuration
But in already created user if I remove the above groups which give warning ,then also it shows same warning.
The solution I mentioned above was for new users,but for some existing users it was still giving problem. So I removed some unwanted groups, which I didn't needed for those users and it worked, now it does not show warning. Was the warning due to some access right overlap or something else?