Q: Photos says version too old after Time Machine Recovery

Thanks for your reply Léonie. When I entered Time Machine I went into the Pictures Folder and in that folder I have Photos Library (icon looks like a stack of photos with the top one being that multicoloured flower wheel), I have a Migrated Photo Library (looks like a stack of photos with the top one being a photo of a flower), and the Photo Booth Library. I clicked on the first one, the Photos Library and hit restore. After it finished everything in my Pictures folder looked normal. I tried to open Photos and I get the "Library Version Too Old" message. I double clicked on the Photos Library in my Pictures folder, same result. I dragged it to the Photos application, same result. 

Since I wrote all this yesterday my External Hard Drive won't backup with Time Machine anymore either. I get a message that reads, "An error occurred while copying files. The problem maybe temporary. If the problem persists, use Disk Utility to repair your Backup disk." I tried to do this and I can't do the repair or unmount the disk. The external hard drive seems to be busy or running something. I can't even eject it. I finally shutdown my Macbook and unplugged it, then restarted the Macbook. I'm not sure if these are related issues as this was all running fine until I tried this restore.

Hey Gerard, thanks for your response. I think you are right, that somehow my Macbook thinks I'm running an older version all of a sudden. I went to About This Mac and hit the software update, nothing came up other than one of my wife games. It says "No Updates Available". The Photos Icon also looks the same in my Pictures folder. I do have a Migrated Photos Library in my Pictures folder as well but whenever I click on that it says the file has already been migrated and doesn't open anything so I don't think that is interfering with anything. I only restored my Photos Library a few hours back in the day because I thought there was a file glitch somewhere in Photos interfering with my wife iPhone syncing... there was probably an easier fix to the problem but I thought restoring from Time Machine was suppose to be easy. I'm sure it is for the most part but this turned out to be a big headache. Any help or additional thoughts on this are greatly appreciated.

One more note, I did what Photos told me to do and I downloaded the iPhotos Library Upgrader (which I didn't need before this) but when I click on it, it asks me to choose a Photos Library to upgrade but they are faded in the finder and I can't choose any of them. It says no libraries are found. That makes me panic a bit.

I mentioned the OS at the end of my post which is El Captain 10.11.6 however I did forget to mention my Photos version which is 1.5 (370.42.0). My Macbook is only about a month and a half old so everything is all up to date. I use to have my iPhoto Library and iTunes all on my External Hard Drive before I started using it for Time Machine because my older iMac had barely any space. When I got the Macbook Pro I put the iPhotos Library and iTunes onto its' hard drive and then used my External Hard Drive for Time Machine. Both Photos and iTunes worked perfectly without any problems until I tried this restore. My first backup was August 17th on Time Machine. Now my External Hard Drive won't let Time Machine perform a Backup. I tried a disk repair but Disk Utility says it can't unmount the drive so it can't perform a repair. Thank you in advance for any advice you can give.

I did command R at start up and then I went into Disk Utilities and I tried first aid on the External Drive. I hope that is what you wanted me to do. This is unfamiliar territory. I understand Disk Utility a little but I'm a novice. At the end of the repair attempt it said it could not verify the Disk and/or repair it. I just got a pop up that stated the same thing and advised me to back up the disk and reformat it. I hope to God I'm not going to lose my photos now. I feel like a goof now trying that restore. What do you suggest next? I hope you have some tricks up your sleeve.

I forgot to mention, one pop up said I could still copy and access files on the External Hard Drive. That's good news at least I hope.