unserialize session error

[eluser]Kenneth Allen[/eluser]
In test and production web sites I see error messages like that below. Each message is identical except for the timestamp. The line below is from production; in the test site the error is reported at offset 150 of 151. I can find no obvious explanation for the error.

Does anyone know what may be causing this error to be produced?

Code:

ERROR - 2010-07-14 15:56:59 --&gt; Severity: Notice  --&gt; unserialize() [<a href='function.unserialize'>function.unserialize</a>]: Error at offset 124 of 176 bytes /home/werowanc/public_html/ontd2ll/SMaLL/system/libraries/Session.php 708

[eluser]Billy Shall[/eluser]
Was a solution for this error ever found?

Thanks

[eluser]WanWizard[/eluser]
This happens when you use database sessions, and your user_data field is to small. MySQL just truncates the field when you update the table, next time you read it, the data can't be unserialized because it is incomplete.

[eluser]Kenneth Allen[/eluser]
[quote author="WanWizard" date="1287365483"]This happens when you use database sessions, and your user_data field is to small. MySQL just truncates the field when you update the table, next time you read it, the data can't be unserialized because it is incomplete.[/quote]
How large does the database field need to be?

[eluser]InsiteFX[/eluser]
The user_data field can be ( text, mediumtext or longtext ).

I changed mine to longtext.

InsiteFX

[eluser]demagu[/eluser]
I was struggling with this issue for a while too.

Turned out that I had wrong ci_sessions table encoding.
After changing it to: utf8_bin everything worked like a charm.

[eluser]InsiteFX[/eluser]
I use utf8_unicode_ci

InsiteFX