Simple client question

[vectorges]

My brother-in-law uses roundcube as his email client. He is a little computer-phobic (and 500 miles away), so  I set it up so he has a bookmarked entry to get him to roundcube. He enters the email address and password and off he goes. Now he got a new computer and he is getting an error message "program not installed on this computer".  I didn't think he needed client software to access his email account. Am I missing something?

[SKaero]

RoundCube doesn't need any special programs to run just a web browser. I'm going to guess he is getting the error elsewhere.