PrivateStorage: Data too long for column 'privateData'

Does anybody have an idea, why the following stack trace is happening?

I’ve checked the privateData column and it’s set to type “text”. Doesn’t it mean, it will accept any length? It’s a MySQL DB.

2015.09.18 14:14:29 org.jivesoftware.openfire.PrivateStorage - Internal server error
com.mysql.jdbc.MysqlDataTruncation: Data truncation: Data too long for column ‘privateData’ at row 1
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4230)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4164)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2615)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2776)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2838)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2082)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2334)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2262)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2246)
at sun.reflect.GeneratedMethodAccessor28.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.ja va:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.logicalcobwebs.proxool.ProxyStatement.invoke(ProxyStatement.java:100)
at org.logicalcobwebs.proxool.ProxyStatement.intercept(ProxyStatement.java:57)
at com.mysql.jdbc.Statement$$EnhancerByProxool$$2654f133.executeUpdate( )
at org.jivesoftware.openfire.PrivateStorage.add(PrivateStorage.java:139)

MySQL :: MySQL 5.6 Reference Manual :: 11.7 Data Type Storage Requirements

The limit for text is 64k, while longtext allows to store much more data.