Hi Jean Philippe,
I found an old SME-9.0 VM with Moodle-2.6.7 installed and running well.
I updated to SME-9.2 and still running.
Installed SCL and updated again. Run well with PHP-5.6.
SCL set PHP-7.1. Not working - white screen.
Returned to PHP-5.6 and working again.
Set PHP-7.1, rename directory to Moodle-old and tried to update to Moodle-3.1. The rights are a little bit tricky but got it and Install was able to write to the top dir but the last installation step not working = error accessing Database.
Rename Moodle-old back to Moodle, return to PHP-5,6 and Moodle-2.6.7 and working again.
For sure, Moodle-2.6.7 is running on SME-9.2,
Michel-André