Professor stopped responding to emails suddenly. What should I do? I am an MS student in France. It is commonplace here to seek out professors from other universities or scientists at research centres to do the MS thesis under them, which is usually during the final semester. So, I reached out to a professor at a US university to carry out my thesis under him. I attached a motivation letter, CV and transcript with the initial email. I also mentioned that I have a scholarship and will not require funding. I heard back on the same day from him and he thanked me for my interest in his research. He said he would like to know a bit more about what I am proposing and went on to ask me about the duration of my thesis, the thesis requirements from my university and what I planned to do following graduation. He ended the email saying he was looking forward to our discussion. I responded to the email within two hours but he never replied. I waited a week to send him another email but he did not respond to that as well. It has been one week since. I do not know what to make of the situation. Is it appropriate to send him another email after a week? I don't understand why he would lose interest all of a sudden when he already had a chance to not respond after looking at my CV?
You have options. 

You could wait and hope. The person is probably pretty busy right now. 

You could try again, but I'd recommend against flooding the person with too many mails or too much information at a given time.

You could cast a wider net and try a few other professors at other places. 

You could give up. 

You could use some combination of the above. But casting a wider net is likely your best option, even in combination with others.