Hi,
This problem can occur if you run a web browser under an administrator account and TestComplete under a non-administrator account. In this case, TestComplete may not have enough permissions to access the browser's data. To check if it is so, go to TestComplete's Object Browser and explore whether the browser process has the Page child node. If the Page node does not exist, the problem is actually in different user accounts.
To solve the problem, run TestComplete under an administrator account. For more information, see Testing Applications Running Under Another User Account in the online documentation.