If you have access to your command line try this:
https://dba.stackexchange.com/questions/14246/innodb-file-format-barracuda (use the commands in bold, below):
you can try this on a test environment first.
mysql> SET GLOBAL innodb_file_format = barracuda;
Query OK, 0 rows affected (0.00 sec)
mysql> SET GLOBAL innodb_file_format_max = barracuda;
Query OK, 0 rows affected (0.00 sec)
mysql> show variables like "%innodb_file%";
+--------------------------+-----------+
| Variable_name | Value |
+--------------------------+-----------+
| innodb_file_format | Barracuda |
| innodb_file_format_check | ON |
| innodb_file_format_max | Barracuda |
| innodb_file_per_table | ON |
+--------------------------+-----------+
4 rows in set (0.00 sec)
Also:
>set global innodb_large_prefix = on;
If you don't have access then try the documentation (as suggested) and tell us what happens. Possibly you are in the wrong forum as well (seems like an installation issue).