Revert back some escape_identifiers() to proect_identifiers() as the first one can't handle arrays
diff --git a/system/database/drivers/mysql/mysql_forge.php b/system/database/drivers/mysql/mysql_forge.php
index 0279b9d..7656c28 100644
--- a/system/database/drivers/mysql/mysql_forge.php
+++ b/system/database/drivers/mysql/mysql_forge.php
@@ -62,7 +62,7 @@
 
 				$sql .= "\n\t".$this->db->escape_identifiers($field);
 
-				empty($attributes['NAME']) OR ' '.$this->db->protect_identifiers($attributes['NAME']).' ';
+				empty($attributes['NAME']) OR ' '.$this->db->escape_identifiers($attributes['NAME']).' ';
 
 				if ( ! empty($attributes['TYPE']))
 				{
@@ -142,7 +142,7 @@
 		if (count($primary_keys) > 0)
 		{
 			$key_name = $this->db->escape_identifiers(implode('_', $primary_keys));
-			$sql .= ",\n\tPRIMARY KEY ".$key_name.' ('.implode(', ', $this->db->escape_identifiers($primary_keys)).')';
+			$sql .= ",\n\tPRIMARY KEY ".$key_name.' ('.implode(', ', $this->db->protect_identifiers($primary_keys)).')';
 		}
 
 		if (is_array($keys) && count($keys) > 0)
@@ -152,7 +152,7 @@
 				if (is_array($key))
 				{
 					$key_name = $this->db->escape_identifiers(implode('_', $key));
-					$key = $this->db->escape_identifiers($key);
+					$key = $this->db->protect_identifiers($key);
 				}
 				else
 				{