This message appears when you open a TestComplete project suite from a network location. You need to choose whether you want to work with the project suite in shared mode or not.
Click Yes to use the shared mode. In this mode, project variable values and some other settings are kept specific to each computer where this project suite will be opened.
Click No to open the project suite normally as if it was on your local computer. TestComplete will use a single collection of settings shared among all users.
Optionally, set the check box to Remember the answer for this project suite and do not ask again. In this case, you can change your initial choice later by editing a configuration file as explained here.