Difficulty putting old photos library from external hard drive onto newer macbook.

I don't think old versions of Photos can be installed on current versions of macOS.

Are these old libraries really from old versions of Photos, or are the from the predecessor program iPhoto? Apple finally removed the code to read from iPhoto libraries from Photos two or three releases ago.

Several of the high-ranked members here swear by the paid program PowerPhotos for copying photos between libraries of different versions, going back to iPhoto.

markwmsn's suggestion of using the trusted 3rd party app PowerPhotos ($30) to import iPhoto Libraries is certainly the best one. And, as he says, many of us use it for handling multiple libraries and some other cool things.

You say that you "Tried to migrate some old memories from photos library from my external hard drive"

I wonder how your are "migrating" these things. Have you tried to double click on the old Library to see if it upgrades and opens? Or what are you doing? But don't try to open the Library if it is on a drive that is not properly formatted!

How is your external drive formatted? To avoid damaging the Photos Library an external drive must be formatted in either APFS format or Mac OS Extended (Journaled) format. Additionally, the drive can not have had Time Machine on it since it was formatted. There have been so many problems with using incompatible drives that the newest macOSs won't even allow a Library on a non-Mac formatted drive to open, since there is a chance of damaging the Photos database. See this:

Move your Photos library to save space on your Mac - Apple Support

Let us know what you find...