Hi Karthik,
Report WDG_MAINTAIN_UR_MIMES is for Web Dynpro ABAP MIMEs. It is not used by the WEBGUI (SAPGUI for HTML).
Please test the WEBGUI service and check in dev_wXX if you have some error message there (WEBGUI related messages will start with "W "). You can also check in SITSPMON whether you have enough memory to hold an ITS session.
Regards,
Cris