Do you have any recent backup? Roon 1.6 build 416 is old as is the year 2019. If you want to restore your recent (listening?) history and tags (library changes?) you need a recent backup to begin with.
What even is the reason why you want to install a backup in the first place? Did you check and resolve the root cause of that initial issue before restoring a backup?
So maybe I have always misunderstood the purpose of the backup. I back up my Synology-based music library pretty regularly. I backup (and now want to restore) my tags, history, and other aspects that are unique to Roon. I take it by your question that restoring is not the way to do so. If that is the case, please advise.
I asked: Why do you want to restore in the first place? Sadly you didn’t answer the question.
Why did I ask? On a healthy and working Roon system there is usually no reason to use a backup. A backup is meant for situation where something happened to a system and data got lost. In such cases there is usually no point in restoring a backup before the root cause for the data loss got identified and resolved (no reason to believe that a backup restore will cure an ailing host system).
If you expect otherwise then your expectation seem to be off to me.
Same with the age of the backup to restore. If you expect to restore the latest state of your Roon system, then you have to use the latest backup (and hope that it is recent enough to contain the latest {important to you} changes). If you expect that a 5+ years old backup will contain and restore latest changes then your expectations seem to be off to me.
The title of your thread reads that you’re unable to restore Roon, the document and screenshots contained show a “Backup successfully restored” screen. So how did you come to the conclusion the restore was unsuccessful? To me it looks like the case as presented so far is based on wrong expectations. In an attempt to figure out what is actually going on with the system and if there even is an incident that you can be helped with and what that may be and how further troubleshooting steps for you might look like, I asked questions. Please try and answer them to help others who are trying to help you.
My initial goal was to restore my tags and history which I thought may have been corrupted. My restore, which as you have pointed out was successfully completed, was from an obsolete backup. And that backup, of course, wouldn’t have my recent tags and history. All is well after I selected a recent backup. I completed that last night.