This is an unofficial & built fork of Pentaho's legacy WAQR (Web Adhoc Query and Reporting), patched so that it works in Pentaho 7.0+
There was a change in the way Pentaho was passing URL paths to WAQR that broke WAQR so that it wasn't able load any saved files. This fork (see 5bf17c8) fixes that problem.
This is prebuilt, so all you have to do is clone this to your pentaho-solutions/system directory:
$ git clone https://github.com/DeBortoliWines/pentaho-waqr-plugin waqr