What’s the state of your car battery? - low volts can cause issues with electric operation of many things. If it’s still on the original battery, I’d check it out as it might need changing.

 

The car battery is less than a year old, and the car is run frequently and I didn’t need to start it between doing the opening operations, I just switched it off, removed the key and tried again.

 

I've never had this particular problem with my roadster, though I have replaced both flap servos - those can prevent the car from acknowledging that the top is completely down. However, I had this problem with my wife's 2007 Bentley GTC. It would stop at random times in the up or down process. I finally determined that the roof position potentiometer was bad so the roof controller couldn't tell where the top was. The TT uses hall sensors and microswitches, rather than a potentiometer, so one of those may be bad. I'm pretty sure there are switches in the roof latches, so if it's halting soon after releasing from the windshield, it could be one of those.

 

I actually stopped the roof to put plastic under it to prevent spray on the windscreen, sorry if it was misleading, I stopped the roof then it wouldn’t re start. Then it did eventually after a few attempts.

 

Ah - okay. Still, could be an iffy hall sensor or microswitch. The next time it happens, you may be able to learn something if you have access to VCDS. That's what I used to debug the Bentley roof issues. I had access to a bunch of sensor status signals and finally figured out the one that was out of place when the roof error occured.

 

Ok thanks, my expert service man hopefully will be able to test that if it occurs again, like I said it’s never ever been an issue and usually the engine is running when I operate the roof mechanism. Thanks again.

 

As mentioned, a VCDS or OBDeleven fault can would be helpful. If it is a Hall Sensor, you won't get a fault code, but with VCDS you can see the binary results if they are working or not.

Good read here as there are multiple links for various Convertible Top related issues.

https://www.ttforum.co.uk/threads/faq-trouble-shooting-the-mk2-roadster-convertible-soft-top-problems-solutions.1953141/?post_id=9310655#post-9310655

Look for Section 2.7 Defective F171 / F202 Hall Sensors

 

Wow, what a comprehensive reply, I will get the fault code read and go from there, thank you. Hopefully it will not be too expensive. The roof has only once let me down and it was a flap issue that was easily solved.