I absolutely agree with the frustration. When there is a match, I do not want to miss, there is nothing more frustrating than to be greeted with an error message. Then you begin the search for resolution and both entities do not provide info that is useful. It was not ideal watching (or try to) the last two matches of the day in Basel.
I had already contacted Tennis TV with full details. I've found them to be responsive in the past (although there was a really rocky start to the season,) It is currently 2:40AM in London so I am not sure that anyone will receive a response before calling it a night in the US.
I will post any info I may receive.
Keep all fingers crossed.
As of 7am Oct 27th the APP is now working again.
Enjoy the tennis everyone!