Problem: If you have .MDB file as your data store for your ASP.NET (assuming hosted under IIS). It will work in your local machine (all CRUD operations) but when you try to access your site from external system which performs update/insert operation, it will throw exception.

Reason : ASP.NET account requires security permission to do CRUD operation on MDB files.

Solution : Add ASP.NET account as a part of Admin user / equivalent to admin user, then assign ASP.NET account to the required site.