OnePager can be launched by either (1) double-clicking on a desktop icon, or (2) by clicking the OnePager button on the Add-ins tab in Microsoft Project or Excel. However, it is not possible to have OnePager running from both places at the same time.
If you received a warning that OnePager cannot launch because it is already running as an add-in, it means that you tried to re-start OnePager a second time via the desktop icon, even though it was already running inside Microsoft Project or Excel. There are two ways to resolve this issue:
Option 1: Go Back to the Add-in
OnePager is already running as an add-in, so if you were just trying to get back to OnePager, you can simply return to Microsoft Project or Excel, and click on the OnePager window that's already open.
An easy way to do this is to click the icon for Microsoft Project or Excel on your Windows taskbar. This will pop up a list of all open windows, including OnePager. Click the OnePager window, and you'll be back to where you started:
Option 2: Disable the Add-in, and Launch from the Desktop Instead
If you prefer not to have OnePager running as an add-in at all, you can disable it, and relaunch OnePager via the desktop icon.
- Return to Microsoft Project or Excel. See the screenshot from Option 1 above if you need help doing this.
- Close all open OnePager windows. This should leave Microsoft Project or Excel running, but not OnePager.
- Disable OnePager as an add-in to Project or Excel by following these instructions.
- Now, double-click the OnePager desktop icon again, and it should launch without the warning.
REMEMBER: You have the option to launch OnePager as an add-in or as a standalone application. Many users like the ability to switch back and forth, which is fine to do, as long as you don't try to run OnePager both ways at the same time. As a result, we only recommend disabling the add-in (Option 2) if you never plan on using the add-in going forward.