windows installer version 1.7 installed : apps intallation causes 'internal server error'

[jitendrashahiitb]

Some apps were installed using 'manage apps'.
But after some ( in one attept after 2 apps, in another attempt on a different PC after 10 apps) apps being installed, the error appears: internal server error

Could this be related to ports being different than ususal. e.g postgresql/postgis is usually on 5432. After installation on windows installer 1.7 , the posrt numbers are displayed. They are different from default.
is there any setting that I may have missed?