Updated June 21, 2016
This article provides steps to resolve the following error when upgrading from NPM 11.5 to NPM 12:
access to the path \inetpub\solarwinds is denied
NPM version 12
1. Rename the SolarWinds folder
C:\InetPub\SolarWinds to C:\InetPub\SolarWinds.old.
2. Rerun the Configuration Wizard to recreate the SolarWinds website.
Upgrade should now complete successfully.