The 'More information about his error' link is just relating to the type of error 'dmlwriteexception' which must means that something went wrong when writing to the database - and there could be many, many reasons for that.
Thank you very much for giving the full debug output. That makes it easy to help. They key bit is "Duplicate entry '58792' for key 'mdl_qtypmultopti_que_uix'" which tells us why the data could not be written to the database - it violated a unique constraint.
For each multiple choice question, there should be just one set of options. However rule was only enforced properly in Moodle 2.5. It seems that your backup file was created in an older version of Moodle, and contains bad data. Now you are trying to restore it into Moodle 2.7.2 and the constraint is checked and is failing.
I note you say "I went to add a course in recently". What exactly where you doing when the error occurred?