When will I see this deployment preview error?
The InstalledPackage metadata type represents managed packages installed in the org, like apps from the Salesforce Appexchange.
This metadata type cannot be added, modified, or deleted through the API. If you try to perform any of these operations with Salto, you will get a deployment preview error.
For example, this is what I see when I try to create a InstalledPackage instance of the Code Builder managed package
Similar errors will appear if you try to modify or delete an instance of this metadata type.
How does this affect my deployment?
The selected package will be skipped and will not be deployed.
How can I fix this error?
Make any modifications to the managed package (or install it if it doesn't exist) from the Salesforce UI or download the package from the Salesforce Appexchange.