Summary
By default, when a file is opened in Excel with a JS add-in installed and then saved, the JS add-in is automatically embedded in the file. In the current design all embedded add-ins will be attempted to load when the file is opened even if the embedded add-ins are the same. As a result, when these files are shared with other users who already have the same JS add-in installed with a different version or deployment method, Excel displays two instances of the same add-in in the tabs, or occasionally shows an error in the task pane if the version it is embedded is an older one.
We first became aware of this issue when a user reported seeing our JS add-in appear twice in the ribbon, which led to confusion. Upon inspecting the affected file’s XML web extensions, we identified two versions of the same add-in embedded: one deployed via OMEX and another via exCatalog. After further investigation and filing a ticket with Microsoft Support, it was confirmed that this behavior is by design under the current implementation.
Why This Matters
While we understand that this behavior is expected by design, it remains problematic for users—it can cause confusion and potential issues with custom functions or with the add-in itself. Also, it is not clear for
As of the moment there are no easy workaround for users to remove the duplicate/additional instance of the same JS add-in embedded in the file, this will also need to be done for every file that is suffering from this issue (has multiple instance of the same add-in embedded in the file w/ different version/deployment method).
Proposed Change/s
Update current design to be able to identify if the embedded adds-in is the same through checking and comparing a unique id so even if they have different deployment/version tags it will not be loaded/attempted to be loaded in the task pane.
Alternatives Considered
- Provide an option in Officejs API to prevent embedding/referencing add-in in a file
Benefits
- Prevents users from seeing the same add-in appear twice in the file
- Eliminate propagating errors in the task pane from trying to render the same add-in with the old version tag
- [Alternative considered] Allow users/dev to be able to control which add-in gets embedded in the file