Visual Studio Online, experiencing error "TF400486: Unable to complete the operation..." when adding new items from the backlog view

Question

We use Visual Studio Online.

We've been experiencing this issue over the past two days, when adding a new Product Backlog Item into the backlog view.

When we add an item from the quick add form in the backlog, TFS displays error TF400486. The item is saved and given an ID number, however, the spinner displays continuously. If further items are added from this screen, they will not save. A screen shot of the error is below.

The full error text is:

TF400486: Unable to complete the operation because you or another user has modified, removed, or re-parented items, or you are trying to reorder an item outside of its immediate parent.

Adding an item via the Work>Queries>New>Product Backlog Item does work correctly.

Any ideas what might be going wrong in the backlog view?

Aerotherapeutics

Is this on one machine only or others? Browser? – Stalactite

Tested on two machines, and both experience the same issue. They are using the same version of Chrome. – Aerotherapeutics

Have you tried another browser? – Stalactite

IE9 experiences the same error and behaviour. Chrome in private mode has the error too. – Aerotherapeutics

IE9?? What OS are you running? – Stalactite

Did you find an answer to this problem? Also encountering on OSX with Chrome – Adequacy

I face this error only when I create an epic from the Backlogs view. From the Work Items view I can create an epic without any issues. – Irrational

Adding this here since this is the top google hit for this error.... If anyone is seeing this error with Azure Devops while attempting to re-order a backlog, the root cause for me is that I was attempting to drag and drop an Epic (with many things below it) that was "Closed". I changed its state, drag/dropped it and then set to back to "Closed" and that worked. – Keyhole

Answer 1

We had this same error and found a workaround. We removed the link to a parent Workitem and then could do Drag & Drop again. This was true even after we relinked the user story with their former parent elements again.

I hope this helps.

We never found the root of this error.

Fervency

This is exactly what happened with our instance of Azure DevOps Server. In this case, the user story was a child to a different user story in another iteration. I recommended removing the relationship and the issue was resolved. – Timecard

Answer 2

Make sure you don't have another iteration path with the same name. If so, it prevents items from being reordered.

In my case I added suffix (2022) on my the old iteration path T01-JAN-01

Uboat

Answer 3

It sounds like a caching issue for that page. Try using private mode (InPrivate) or clearing the cache for that browser.

Stalactite

Dam, then you should raise a support request with the VSO team. Go to visualstudio.com and click support.. – Stalactite