This "failed to create directory" failure is normally caused by insufficient hard drive space or lack of folder permissions. You may try the following:
1. Run DVDFab 13 as administrator;
2. Change the Save To target from the default drive C to other drives with a larger free space;
3. In DVDFab Common Settings > General > General panel, change the Temporary Directory to another drive if you are doing Copy as it needs at least 20 GB disk space for saving the temp file.