There isn't a version of Configurable Reports that officially works with Moodle 3.4. The Configurable Reports block hasn't been upgraded since Moodle 3.1. Juan, the developer, now heads up the Moodle Mobile team at the Moodle office in Spain and it seems he doesn't have time to update the plugin...
You can get the latest official version from https://moodle.org/plugins/block_configurable_reports. Download the .zip file from there and then extract it to the Moodle folder on your server. Some people say it still works - but with some issues. It depends on what functionality you are using...
If you have any major problems with it, try the forks that have been released by other developers who depend on Configurable Reports but couldn't wait two years and five Moodle versions for an official release.
Example: https://github.com/michael-milette/moodle-block_configurablereports.
Look in the Moodle Tracker for issues relating to reporting in Moodle and you'll find issues like:
https://tracker.moodle.org/browse/MDL-63233
https://tracker.moodle.org/browse/MDL-62080
Read the comments in those MDL issues for interesting suggestions.
If you don't want to rely on hacky fixes to unmaintained plugins then consider joining the Moodle Users Association (MUA) and vote for the Customizable Report Builder proposal.
If you can't afford the risks of using an unsupported version of Configurable Reports and you can't wait for any unconfirmed solutions from the MUA then try the Ad-Hoc Database Queries (customsql) plugin from the Open University. It does roughly the same thing as Configurable Reports (lets you run your own sql queries) and has been around for a long time.
Luis
Thanks for taking the time to provide such information. I will follow your suggestions!
Ken
Our internal policy is to make a shadow copy of sites and test all upgrades and modifications on it.
So, we're covered in this regard but, thanks for the reminder Luis!
Ken