Tailgate and driver's door handle
 

I had the same 2 problems this morning and yesterday morning.

The tailgate wont open or close.
The latch gets released, but the tailgate wont open. I could open it by forcing it all the way up. Then, pressing the button wont close it. I had to force it again to close it. After driving away everyting was functional until this morning that the problem repeated itself.

Same with the driver's outside door handle. It gets really stuck. It does become operational again after forcing it the first time in the morning.

Why is all this?

Where are you located and what kind of overnight temps have you been having lately?

Assume you have an electric tailgate lift?

Yes, electric tailgate lift.
I'm located in Montreal, Canada.
Believe me, it's not as cold as we're use to get, but it's been going down below 0*C. These 2 last mornings it's been -10*C (14*F).

Make sure the battery is not weak or low on charge as well.

14F may be cold enough to cause grease and other things in the door latch to have problems.

I hooked up my trickle charger. I'll leave it overnight and see how it reacts in the morning. I did got a low battery warning 2 weeks ago, but I completely slow charged it right away.

So one thing I forgot to mention, some of the E70 have NO WAY to warn the driver if the charging system has a problem!!!

I know for sure many if not all of the V8 engines have this problem, not sure if other engines are the same. There may or may not be a software update or maybe this problem is a MASSIVE oversight by BMW. You can remove the serpentine belt and you will receive NO warning that there is a charging problem. You will get a low battery warning if you are sitting and using accessories, but I never received a low battery warning when the alternator was not charging.

What engine do you have in your vehicle?

Will be interesting to see what happens coming right of the charger.

I got a 35d.
If I plug a multimeter I should get a reading of 14v. Shouldn't I?
I'm not sure about the diesel version, but I believe the gas ones use BER system.

A fully charged battery typically has a surface Voltage of around 12.6 Volts.

Typical charging Voltage is between 13.5-14.5 Volts.

If you measured 14 Voltage at the battery, it probably has a surface charge that can be knocked down by turning the headlights on for 2 minutes.

Well, the problem is not due to the battery.
Same situation this morning. Trunk tries to open, but it looks that it senses some force and stops. Door handle was a bit stuck, but not as hard as the previous mornings.
Battery fully charged. Weather 25*F.
One other thing to try, I've been parking the car nose down on my driveway. I usually park it nose up. Physics?

Any moisture/ice that may be causing problems?