Here's a context.
Sales team is thinking of expanding their business in Chinese market, but one of their members, who speaks fluent Chinese, has been assigned to work in the marketing department. So the team leader is really worried that it could become a serious problem doing business in Chinese markets.
And now, as a person in personnel, I'd like to do something for them. So,
Seeing that you are in trouble doing business in Chinese market, we need to do something for you. After checking into the situation, we've decided to let him with you.
Here is it possible that I write doing business in Chinese market right after trouble in the same way that we do in this sentence: We have a trouble doing our business in China.
Best Answer
The meaning of the phrase in trouble:
is different than trouble, which generally means difficulty or distress.
In your example, you mean that you are having difficulty doing business, but you are not in danger or under threat of punishment (I hope). Therefore you should use having trouble:
In the definitions, one for in trouble is "in difficulty" but this more refers to a specific personal impact, not to a transactional situation.
BTW, let is not used properly, I can't tell for sure but maybe you mean leave?