Hi,

Yes, it looks like "User Manager" allows any character to be entered for "User Name" but it shouldn't as SqlMembershipProvider doesn't allow commas (that seems to be the only problematic character). 

As a workaround you can try to edit the field manually and remove the comma.

I've filed a bug report about this and we will fix it as soon as possible.

Thanks!

but the username I use is admin. And there is no comma in it.

Can you please check the actual data in the database?
Does this happen with default installation, if not can you provide a sample that triggers the error?  

Regards,
Igor

This happens with the default installation of MonoX. I have not done anything with the users. i have just setup a few custom pages. 

Well, this happens when I click on edit button on the profile edit page with the default installation. 

The page url is domainname.com/profile-about/admin/

We had is issue before, source of the problem and possible solutions are offered here:
http://www.mono-software.com/Mono/Pages/Discussion/dtopic/x1XtGX4IcE-9R56KATl6gQ/I-have-latest-monox-up-and-running-Error-when-trying-to-design-or-edit-profile-pages/?dbmpageno=0 

Hi Idrazic,

I have placed the  Form.broser in the App_Browsers folder and it works fine on the web server but does not work on my local development machine. Also it will be great if you can add some URL rewrite rules that you have used and explain them in the documentation.
Thanks very much for your help. 

is there a reason why the form.browser file wont display the login page which is placed in the root directory?

Let me try to fill in a few blanks here ...

This will work only in the scenario where you have a Form.browser in the App_Browsers folder and you have removed the App_Browsers.dll from your bin folder.
URL Rewriter used by MonoX can be found here. As MonoX doesn't implement any custom rules or anything you can find all the documentation you need on that link. Let us know if you need any more information regarding the rewriting ?

Form Adapter (Form.browser) is used to rewrite the HTML Form action attribute on all forms in MonoX to get URL rewriting ability and to fix the postback issues when you use rewriting etc. Login page is not rewritten so there should be any link between those two.
Regards