If you encounter this message while running BT, it could be one of 2 problems. The first one is the DEP problem – discussed here – so I won’t discuss it anymore.
The second problem is the presence of old API versions and components lingering in your system. IB made several upgrades to their API and when you install a new one, the old versions are left behind. When an updated BT runs, it will still connect to the old components. BT does not package it’s own API (like some other programs) but depends on the original API’s from IB. The way to solve this is to uninstall the API through the Control Panel. The program should be labelled TWS_API. You can also check your C:\ folder to see if there is something like an IB_API_968 folder. If there is, go inside the folder and click unwise.exe to uninstall the program. You might also uninstall the Visual C++ 2005 redistributable through the Control Panel. When you install back the programs – get them from the BT download site – then install the programs in sequence.