Concurrent Editing and Conflict Resolution
The Ignition Designer uses a lock-free strategy for handling concurrent editing. Multiple people can work together and make changes to a project at the same time. An unlimited number of Designers can be open concurrently, and modifying any resource in the Designer doesn't lock it. The Designer keeps track of the resources that are being edited, and any conflicting edits will be resolved at the time the project is saved. The developer who creates a saving conflict will be prompted to resolve the conflict by choosing whether to use their own changes, accept the other designer's changes, or cancel their save and figure out what to do in another way.
Concurrent Users UI
The Concurrent User Interface allows users to see which project resources are open in other Designer instances, the names of the users that have them open, and when a project update is available. The UI is located in the lower right corner of the Designer.
If you open a resource that is already open in another Designer, you will be greeted with a new popup confirming that you want to proceed.
The UI makes use of the color red to denote when there are conflicts with the changes in another Designer instance, or if their users are saving on overlapping resources (multiple users are making changes and saving while the same resource is open).

If the user in the other Designer instance saves their project, the UI will display that a project update is available. Click on Project Update Available to either update or cancel the project update.
Conflict Resolution
When you're ready to save your project, go to the Menubar and select File → Save . When the Save Project dialog pops up, select the items you want to save and click the Save button.
If there are any conflicts, the Designer will ask you to update your project and the conflict resolution screen will open automatically. You will see a thumbnail image of both screens and the .json code showing the conflict. To resolve the conflict, you will be given a choice; accept your changes, accept the other developer's changes, or cancel the save and contact the other developer. Buttons are provided at the top and bottom of the screen for you to enter how you want to resolve the conflict.
The Resource Tree displays the conflicts and the resolutions. The selected conflict will be highlighted in blue. The image below shows changes were made to the Thermometer. The line number and the code are highlighted at the bottom so you can quickly identify the conflict. Once the conflict is resolved, a checkmark will appear in the Resolution column next to the conflict and how it was resolved. You'll notice that there is second conflict. To resolve the conflict, select it in the Resource Tree or click the arrow to navigate to the next conflict.