Did you save and sync it to Garmin Connect before you deleted it? If yes, then you can send it to the 945 if you want on the device for some reason. Use Garmin Connect Web to do that.
I did a multisport, but had an extra set in there. I went to delete just the erroneous set, and it deleted the whole multisport. I had already saved it to my phone app.
If you''ve saved it to your phone then you should be able to download the original .fit file Garmin Connect Interweb. There'll be little point putting it back on to the watch as the data will already have been added to your training load etc.
