Elements of the error message include:
Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column
this is incompatible with sql_mode=only_full_group_by
Filename: libraries/Datamapper.php(1) : eval()'d code(3) : eval()'d code
Line Number: 1348
Your server MySQL module is set to use "only_full_group_by" mode.
The quickest fix would be to disable the "only_full_group_by" mode.
Where you have access to the server as root user, edit:
Look for the "sql_mode=..." line and remove the ONLY_FULL_GROUP_BY value from the line.
After the file is changed save it. Then restart MySQL service ( service mysql restart )