Excel add-in NOT using Visual Studio and/or deploying to AppSource?

Question

I have located the Add-in folder on my computer and copied manually the demo app explained in this video.

However when I try to open the Stock sample data Excel spreadsheet, I get the following error:

ADD-IN ERROR This add-in is no longer available: add-ins inserted during development are only available during debugging from Visual Studio. Please open your project in Visual Studio and re-run your application, or deploy your add-in into a valid catalog and re-inser

Isn't it possible to create an add-in just by using html/javascript files and a manifest? or am I looking at the wrong folder/file?

EDIT: I have tried the 2 solutions suggested here:

• https://xomino365.com/2016/03/15/getting-started-locally-with-a-basic-o365-word-add-in-no-web-hosting/

• https://learn.microsoft.com/en-us/office/dev/add-ins/testing/create-a-network-shared-folder-catalog-for-task-pane-and-content-add-ins

ie using localhost trick or sharing with myself, I still can not see my add-in in Developer/Add-ins/Shared Folder

Answer 1

I faced the same issue. repair ms office and then it'll work hopefully. I my case it worked after I repair the office package

Answer 2

Actually I managed to resolve my issue by using the first solution indicated in the EDIT: using \\localhost\C$\Users\etc... Now my add-in appears in the trusted add-ins catalog.

Wasn't working because I had done a spelling mistake $C instead of C$