If user clicks on lookups then lookup form will display but the selected value will not reflect in to the text box.
Solution: Disable IE ESC for the users
1. Open the Server Manager Tool. Configure IE ESC is located on the right hand side of the interface in the section heading Security Information.
2. Select the link Configure IE Esc and the configuration window will open. At this point you can choose whether to turn off IE ESC for Administrators or for Users or for both.