A script run to ensure that characters are all lowercase changes system values which then causes an error in the user validation.
A script is run to change the case of characters all to lowercase. When the script was run against values stored in plain text, changing an uppercase character to lowercase changed for example the value of the User name of Password. This results in the SYMMETRIC KEY not being created.
The latest K2 Update is available as an independent installation package which can be found here: https://portal.k2.com/downloads/bp/default.aspx.