Trados 2015: the process ís unable to access to the file......


Hi there,
I installed Studio 2015 on my new laptop under Windows 10 pro.  I entered  the activation code. Trados 2015 starts und shows the dashboard. I created a new project and imported in my project several Word files.
Trados reports errors : the process ís unable to access to the file: c:\users\mail\appdata\local\Temp\SDL TempFileManager\...
It occurs also when I open a new package from client.
How to fix this severe issue ?
Regards,