A Membership Provider has not been configured correctly. Check the web.config settings for this web application. FBA configuration AX dynamics 2012

while configuring claim base login for dynamics ax 2012 with sharepoint 2013, I configured everything, but while going to Site Settings > FBA User Management , I got the below error

"A Membership Provider has not been configured correctly. Check the web.config settings for this web application."

but I thoroughly checked all my configs are correct, including the membership and permissions in DB as well.

finally I found that my app pools ( Ep site and STS site) were running in different accounts. hence causing this issue.
finally I make them all same and all were OK.

Regards,
Yes.Sudhanshu