Avoid a network
Avoid non-ascii characters in file- and pathnames and the username
Try running Creator as admin
When all fails, I would suggest you to get in contact with Cypress directly. At top of this page use Design Support and create a support case.
Posting the case conclusion:
It seems the issue is because [somehow] the config.hex is manually deleted from the Generated Source folder.
If any file is deleted outside of PSoC Creator, the project specific files will not get updated[CYPRJ]. So the PSoC Creator doesn't know the config.hex is not there and it will not regenerate.
We can easily solve this issue, you just need to delete the "Generated Source" folder from the PSoC Creator "Workspace explorer". Then build the project, the issue will be resolved.
Thanks and Regards
Deleting Generated Source actually did not work, plus caused some other problems. For me, the real solution is to check Enable Error Correcting Code (ECC) setting in the System Tab. This makes is so that config.hex is not needed and the project will compile. If I clear it it still fails, so there is some other issue. Note this is a CY8C3446LTI-073 project.