Web Part error after Request Management Configuration

Question

Dear All,
I'm so confused in RM, because when ever I trying to open the site pages throw error message like;
Sorry, something went wrong
An unexpected error has occurred.
Web Parts Maintenance Page: If you have permission, you can use this page to temporarily close
Web Parts or remove personal settings. For more information, contact your site administrator.
Uls log with corresponding correlation:
Mapping URI from 'http://portal.domain:80/Pages/Faq.aspx' to 'http://server-sp1/Pages/Faq.aspx'
I was keep refreshing the page default site randomly coming up the site.  But there was no error while accessing site settings and site content and all default SharePoint back end pages on both default/intranet site.
The application urls are;
Server 1: http://server-sp1:4421
Server 2: http://server-sp2:4421
AAM:
http://server-sp1:4421 Default http://server-sp1:4421
http://server-sp2:4421 Default http://server-sp1:4421
http://portal.domain.com intranet http://portal.domain.com
RM configuration:
RoutingRules                       : {portal.domain.com}
ThrottlingRules                    : {}
MachinePools                       : {All WFE Servers}
RoutingTargets                     : {server-sp1, server-sp2}
Rule: portal.domain.com
MachinePool    : SPRoutingMachinePool Name=All WFE Servers
Name           : domain.com
Criteria       : {}
ExecutionGroup : 1
Expiration     : 12/31/9999 11:59:59 PM
Criteria:
PropertyType     : Host
Value            : portal.domain.com
MatchType        : Equals
CaseSensitive    : False
CustomHeaderName : 
How can I resolve this issue?
Thanks in advance.

Answer 1

Sorry for the late reply.  The application was already extended to IIS, what do I need to do in IIS? Even i performed app-pool recycle and iisreset.  No luck.
Thanks.