My department head and I just installed Sharepoint 2013 and Project 2013. We're fairly new to both. I created a Project Web App, and made a project. I was able to add a few tasks to this project.. at first.

Now: I can click Edit on the Project Details Page, check out the project, make changes to the "Project Details" and successfully save. But if I go to "Schedule", I receive this error message:

Your session became invalid because this project was also opened in another browser.

Even for new projects.

I've tried clearing my cache, restarting the computer, trying on a different computer, and doing all that after making sure all projects are forcibly checked in. Googling that error message brings up three total results, all from the same guy dealing with a different cause.

I'm at a loss. Any ideas?


1 Answer 1


I have just stumbled upon this after having received the same error in Project server 2013 and had discovered that it was being caused by there being two 'Project Details' web app parts on the same page.

In our installation of Project server, we have a 'Schedule' page which displays the project schedule (obviously) and somehow, someone had managed to edit the page and add a second 'Project Details' web part to the page, saved it and published it. This meant that whenever one of our PMs accessed the schedule page of the project, the system was attempting to display 2 project schedules hence the error message.

In this scenario, the fix is to edit the page again and delete the duplicated 'Project Details' web part, save and publish.

Hope this helps someone!

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