"File Error" window pop-ups when running multiple instances of QtCreator

When multiple instances of QtCreator running, it whery often "File Error" window pop-ups whith text "Cannont write file C:\Users\user\AppData\Roaming\Nokia\toolChains.xml. Disk full?". Disk doesn't full. So i need to close all QtCreators except one, wait some time, and then launch QtCreators again throw some time. But if they work together several hours (days) its begins again. And they try to write toolChain.xml simultaneously after Hybernation.