Start up error

[teignnews]

Win 7, Radeon 4850, AMD quad core

Upon starting the game, I get to the splash screen, click OK and get:-

Runtime Error
..\..\..\..\Common\plugin.cpp: 7458
Failure Condition: pluginEntryTable.GetEntry(entrypointName, out)
can't find plugin method DecodeBase64(data As String, encoding as TextEncoding = nil) As String

No idea what that means but no different OS, cards, CPU etc. since it used to work.
Any help appreciated

Thanks

[IainMcNeil]

Can you try reinstalling and updating your drivers to see if it helps. If it used to work something on the machine has become corrupt or changed which has broken it.