We have a site that has a number of web applications in it, each a different folder that has been “converted to app” in the IIS interface.
The main site creates a cookie named hsdCP_User, when the user navigates from the main site (ex: apps.mysite.com) to the apps.mysite.com/tickets <which is a WiseJ app>, I get the error in the title.
If I remove the cookie, wiseJ works fine.
Wisej only adds 1 cookie with the session id using a guid string. This error seems to be related to the main site configuration and probably other cookies. See: https://forums.asp.net/t/1930540.aspx?A+potentially+dangerous+Request+Cookies+value+was+detected+from+the+client
Wisej can also work without cookies, see the cookieless sessing in the config section.