3
The important one to fix of those two errors is the second one (the one about ret is not important - but fixed in 2.0.7 anyway)
It is done by loading up modules/system/admin/groupperm.php and change line 21 from
if (false != $gperm_handler->deleteByModule($modid, $permname)) {
to
if (false != $gperm_handler->deleteByModule($modid, $perm_name)) {
and uploading the file to overwrite the existing one.