The temp folder is a folder for temporary files created by iClone during operation. You can define where temporary files are saved in the preferences settings.
Click the Preferences
button to display
the preferences dialog box.

Click the Choose...
button in
Temp Folder option and browse to
a folder to use as the temp folder.
Click the OK button when finished.
Make sure the temp folder has sufficient HD space especially you are using iClone to produce high resolution Videos.