A user or group is able to upload to all Document Types if they are given: Create Document Permission on the base Document Type.

Check if the account has access to Upload documents. Verify that the user has a Create button in the ribbon across the top of the UI.

To assign the correct permission, an Admin needs to do the following:

1. Click on Admin Gear in the ribbon.
2. Click on Configuration.
3. Navigate to Document Types.
4. Select the Document Type to which the user needs permission.
5. Hover over the action wheel and click Edit Details.
6. Click the Security tab.
7. Add the user or group to the Create Document Permissions list.

Related Documentation:

Vault Help Documentation: Configuring Document Types