Note: You are currently viewing documentation for Moodle 2.8. Up-to-date documentation for the latest stable version of Moodle may be available here: error/tool installaddon/err curl exec.

error/tool installaddon/err curl exec

From MoodleDocs

This suggests problems with the validation of the SSL certificate of the remote ( site. This is also a known problem in Moodle Windows 7 servers running the Moodle package for Windows. See SSL certificate for for more info and possible solutions.