Confirm the installation
Move diCleaner to Applications and open that copy. Do not run it permanently from a disk image, archive, or Downloads.
Read the macOS message
If macOS blocks the app, confirm it came from the Mac App Store or official Doinno website. Open System Settings → Privacy & Security and review the exact security message.
Do not bypass a warning when the developer or source is unexpected.
Remove duplicate confusion
Search for other copies and quit them. A beta, App Store edition, and direct edition can have separate permissions and behavior.
Replace a damaged copy
Download the correct edition again from its official source. Quit the old copy, replace it in Applications, and reopen.
Restart
Restart the Mac when a previous process or update remains stuck. If the app still does not open, record the macOS version, Mac model, diCleaner edition, and displayed error.