Choose File > Back up Project and pick an empty folder on the backup drive. Cubase writes the project file there with a copy of every file it uses, including audio recorded or imported from outside the project folder. Copying the project folder by hand misses those outside files, and copying only the .cpr misses everything: the project file points at its audio, it does not contain it.

Back up a project

The Back up Project Options dialog has six settings:

• Project Name: the name of the copy.
• Keep Current Project Active: keep working on the original after the backup is written.
• Minimize Audio Files: copy only the parts of each audio file the project uses. The backup gets much smaller when you used short sections of long recordings, but the rest of those files is gone from the copy.
• Make Direct Offline Processing Permanent: renders your offline processing into the audio, so the copy does not depend on it.
• Remove Unused Files: copy only files the project uses.
• Do Not Back up Video: leave video clips out.

For an archive, leave Minimize Audio Files off so every take survives. For a handoff, turn on Remove Unused Files.

Version a project and roll back

File > Save New Version (Ctrl+Alt+S on Windows, Cmd+Option+S on Mac) saves the project under its name with a counter: My Project-01, My Project-02, and so on, and you keep working in the new one. Every number is a complete project to go back to.

For crash insurance, turn on Auto Save in Preferences > General. Cubase periodically writes backups of open projects with unsaved changes as .bak files in the project folder. Auto Save Interval sets how often and Maximum Backup Files how many; past the maximum, the oldest is overwritten.

Send a project to another studio

Back up Project into a new folder, zip it and send it. Note the Cubase version you saved with and every third-party plugin the project uses, since plugins are not part of the backup.

For someone on another DAW, Cubase Pro and Cubase Artist 14.0.20 and later can export a DAWproject (File > Export > DAWproject), the open format Studio One and Bitwig read. Steinberg lists gaps in it (no tempo track and no MIDI controller data in the first releases), so check the result before you rely on it.

Export stems for mixing or mastering

1. Choose File > Export > Audio Mixdown.
2. In Channel Selection, click Multiple and tick the channels to export. Cubase writes one file per channel, with its MixConsole settings and insert effects. Batch export of several channels is a Cubase Pro feature.
3. Choose how much processing to print from the Effects menu, which appears once Multiple is on: from inserts and channel settings only, to dry, to including groups, sends and the master.
4. Use a naming scheme with the channel name, and export the whole project range so every file lines up.

Doing it in Aden

Cubase's .cpr is a closed binary format. Aden syncs and versions it, and plays your project in the browser when you export a DAWproject beside it.

• Your projects, listed. The desktop app finds .cpr files on your disk and lists them on Home.
• Sync the project folder to a track (Max plan). Every save is pushed. A collaborator clicks Pull for the latest files; a pull never overwrites their local edits, it saves the incoming file as a versioned copy beside theirs. Every synced file keeps its version history, downloadable from the track's Project files page.
• A check before you send. Send as a transfer zips the project folder into a link that expires in 30 days, and tells you to run Back up Project first when it holds little more than the .cpr.
• Hear it without Cubase. Export a DAWproject into the synced folder and the Project files page reads it: tempo, tracks, devices with their plugin format, clips and notes. Press play for a sketch of the arrangement with your audio; third-party instruments get a stand-in sound. Without a DAWproject, it plays the bounce linked to the project, or the track's final version.
• Record and edit together. With a DAWproject, move or delete clips with everyone on the page and Save writes them into the .dawproject; vocal takes recorded in the browser are written into it as clips on a new track. Without one, takes land in an Aden Takes/ folder in the project, named by the bar to drop them at.
• Feedback on the bounce. Export the mixdown and the desktop app notices it: named after a track you have, it offers it as that track's next version. Send a share link and people comment at a timestamp or on a section of the waveform, with no Aden account needed on a link with comments turned on. Send for review asks them to approve it or request changes, and Compare flips between mixes at the same playhead.
• Stems on a version. Upload your exported channels to the version's Stems tab to play them together under the mix.
• Aden inside Cubase. The desktop app installs Aden as a VST3 plugin on macOS and Windows. Put it on the stereo out to see the track's notes, lyrics and session without leaving Cubase.

Sources: Steinberg, Back up Project Options dialog, Saving project files as a new version, Preferences, General (Auto Save), Export Audio Mixdown dialog, Steinberg Help Center, DAWproject. See also how other DAWs version projects.