There are switches mounted to the top latches which signal the top controller that all is secure. One of your switches may be faulty or incorrectly adjusted. You should be able to diagnose this by putting the top controller in diagnostic mode. You will need no special tools.
1) Close the soft top manually or automatically. Have the windows up. The correct position for the roll bar depends on the version of your soft top controller. Let's assume it is the raised postion. If this is incorrect, a fault code for the roll bar lowered switch will falsely appear later in the test -- no big deal.
2) Erase as many diagnostic codes from the soft top controller as possible. This is very simple to do and is explained
here.
3) Switch off the ignition.
4) Install a jumper between sockets "1" and "3' of the "X11/12" connector located behind the passenger-side footrest. This connector is shown in the photo below.
5) Switch the ignition on.
6) Push the soft top button forward for two to four seconds as if you were trying to close the top.
7) Read out and record any diagnostic codes for the soft top controller.
8) Remove the jumper from the connector X11/12.
9) Lower the top, roll bar, and windows either manually or automatically.
10) Open the soft top compartment cover and move it to its raised position. I recommend doing this manually. Use the special Mercedes wrench to release the latches if necessary.
11) Switch the ignition off.
12) Re-install the jumper on X11/12.
13) Switch the ignition on.
14) Push the soft top button rearward for two to four seconds as if you were trying to open the top.
15) Read out and record any diagnostic codes for the soft top controller as explained in the thread noted in "2" above. Any codes you find will identify your problem. If you email them to me or post your findings back here, I can interpret them for you.
16) Remove the bridge.