Steps to reproduce

1. Create a course or go to an existing one
2. Add a "configurable report" block
3. Click "Manage reports"
4. In the "Import report from repository" section, in the "Categories" drop-down list, switch the category from "..." to any other the following actions must be performed quickly switch the category back to "..." and in the "Report" drop-down list, select any report named README

The result

error/errorimporting

Error:
Error code: errorimporting
$a contents:

Stacktrace:
line 70 of /blocks/configurable_reports/managereport.php: moodle_exception thrown

Expected result

There are no reports with the name 'README' or 'undefined' and there are no errors either