Every new month I archive (backup) all LC data from Empower to our server. When finished I delete the data from the month before.

Now I need data (5 standard injections) from last month (backed up) to quantitate data from this month. But Empower keeps giving me an error.

When I try to copy the restored data from last month to the project where the new data is I get:
Instrument method, XXX from a different origin already exists. It cannot be replaced at this time because it is referenced by other objects. Note: Delete those objects first before you delete the method.
Is there a way I can combine archived data and new data?