Recently I was trying to develop a SharePoint hosted add-in using visual studio 2015 and was trying to deploying to a SharePoint online developer site. But while deploying I got the below error, even I tried to deploy multiple times but every time it throws some error.
The error message comes as:
Skipping the uninstall step because the SharePoint Add-in is in an invalid state and cannot be uninstalled.
Error occurred in deployment step ‘Install SharePoint Add-in’: An instance of this App already exists at the specified location
Sometimes the below error also came:
Error occurred in deployment step ‘Install SharePoint Add-in:’ The remote server returned an error: (503) Server Unavailable.
The errors were looking strange because I have not modified anything while developing the add-in, it was just a basic add-in without any customization. But still it was giving the same error, even I tried to redevelop the SharePoint hosted add-in but no success.
Sometimes the add-in did not uninstall properly then it will give an error like above. In those cases, you can remove the add-in from “Apps in Testing” in the developer site. You can select the add-in and then click on … and then click on REMOVE button like below:
Alternatively, you can also remove the add-in from the Site Contents page, Open the Site Contents page and then click on … and then click on Remove like below:
In my case it was different, Then I found out that there is a Service degradation in the SharePoint Online going on in the Office 365 tenant.
That information I found in the Office 365 Admin center Servce health section.
The below was the full message.
User impact: Admins may have been unable install or activate SharePoint add-ins or SharePoint Framework solutions.
Latest message: Title: Can’t install or activate SharePoint add-ins or SharePoint Framework solutions
User Impact: Admins may have been unable install or activate SharePoint add-ins or SharePoint Framework solutions.
Final status: We’ve completed deployment of the fix and confirmed that service has been restored.
Scope of impact: This issue could have potentially affected any admin attempting to install or activate SharePoint add-ins or SharePoint Framework solutions.
Start time: Monday, February 5, 2018, at 5:00 AM UTC
End time: Thursday, February 8, 2018, at 8:00 PM UTC
Preliminary root cause: A coding issue resulted in a problem in which admins were unable to install or activate SharePoint add-ins or SharePoint Framework solutions.
– We’re reviewing our update procedures to better identify similar issues during our development and testing cycles.
Once the Service restored, I am able to deploy the same SharePoint hosted add-in without changing anything.
Read some SharePoint Add-in tutorials below:
- Configure Add-In or app development environment in SharePoint server 2016
- Video Tutorial Create and Deploy SharePoint Hosted Add-in using Visual Studio 2015
- Provider Hosted App in SharePoint Online using Visual Studio 2017 + Deploy Provider Hosted Add-in to Microsoft Azure
- Remote Event Receivers in SharePoint online + Develop in Provider hosted Add-in using Visual Studio 2015 and Deploy to Microsoft Azure
- Create choice type site column and add mapping inside SharePoint hosted add-in using visual studio 2015
In this tutorial, we learned how to fix error, Error occurred in deployment step ‘Install SharePoint Add-in’: An instance of this App already exists at the specified location.
Hello Everyone!! I am Bhawana a SharePoint MVP and having about 10+ years of SharePoint experience as well as in .Net technologies. I have worked in all the versions of SharePoint from wss to Office 365. I have good exposure in Customization and Migration using Nintex, Metalogix tools. Now exploring more in SharePoint 2016 🙂 Hope here I can contribute and share my knowledge to the fullest. As I believe “There is no wealth like knowledge and no poverty like ignorance”