Another issue I just faced on a Migrated SharePoint Environment at one of my client today. they were in SP 2007 and recently gone in to 2010.
Problem Statement : the issue is, Designers in various divisions unable to edit web parts on their pages. going in to edit mode through Edit page is possible and whatever the features in ribbon such as web part options/permission also exists and functioning properly but once web part selected it doesn’t allow to edit, can be just highlighted (basically read mode). these designers has been granted with Design permission and previously in SharePoint 2007 this issue wasn’t exist.
Thanking to SharePoint Warriors, finally got a point of solving somehow so stating here it for you who needs it out there.
Cause of the problem is a new setting in SharePoint 2010 that allows us administrators to restrict contributors/designers from editing web parts. So you can do one of two things to fix this problem.
Option 01 – Disabling Security Feature from Web Application level at Central Admin
Note: this setting can only be enabled at web application level. it applies to whole web application.
Direct to Central Administration –> select your web application that you want to make this change on –> select ‘Web Part Security’ —> scroll down to ‘Scriptable Web Parts’ and –> select ‘Allows contributors to add or edit scriptable Web Parts’ –> click OK
Option 02 – else if you need to keep above security enabled further, just try on giving Approve, Manage, Design permissions instead Full Permission.