CST 2015 Wrong storage basepath Error

i need help in resolving an error i have been facing in CST software. The error appearedis "Error while initializng storage. Wrong storage basepath". I have changed the storage location, even try to run the CST file from external hard drive but it still didnt work. Even i have reinstalled the software 3 to 4 times but after first 3 4 successful runs, it again started showing this error.