Recently while working with developing a SharePoint hosted add-in, while deploying the add-in, I got the error as Error occurred in deployment step ‘Install SharePoint Add-in’. Sideloading of apps is not enabled on this site. It looks like below:
– Introduction to new SharePoint Online Site Contents page
Actually while developing a SharePoint hosted add-in you should give a developer site. You should create a developer site using the developer site template and you should give that URL in your visual studio reference.
You can follow How to create developer site in Office 365 SharePoint 2013 Online? and also you can check the SharePoint 2013 Developer Site Template overview.
The above solution works for me.
Also, you can check the below solution which I followed from this MSDN article.
Enable-SPFeature e374875e-06b6-11e0-b0fa-57f5dfd72085 –url http://SiteURL
Hope this will be helpful.
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