Have you installed the clipart ? Once you have downloaded from the portal you need to install the files. Double click on the downloaded file & then follow the instructions on screen. Or single click, then right click & select open.
The files will install into the right folders within the software & then you should be able to see & use them once the Vectric software is open.
If the files are downloaded & installed into a custom folder then Adrians advice might help.
If you are constantly having problems with them not opening or not being found then try re installing them, if you still have problems then it may be a hard disk problem