Could not access Apple Photos Library

[jasonb42111946]

Hello - I am trying to move my Apple Photos Library which is very large (80 gigabytes and 20k photos) to Lightroom.  I had to upgrade the Mac OS to Catalina which has really slowed down the machine.  I tried to 'Prepare Apple Photos Library for Migration' steps by selecting library as System Photo Library and then started the migration in Lightroom. The problem is the process never finished -- I let the computer sit there for a week and it froze and never recovered so I had to hard reboot.  Now I go back in and try the process again and it says "Apple PHotos Library is Missing or Damaged" or "Lightroom does not have correct permissions"....  I opened the Photos Library on the Mac after the re-boot and I can navigate it fine.  How do I fix this so I can re-start the import?  I am trying to preserve a complex scheme of folders and albums I have in existing Photos library. 

[selondon]

As this is mainly a user to user forum, it's probably worth posting on the following forum also, which is monitored by the engineering team, who may be able to give some detailed advice on how to solve your problem:

https://feedback.photoshop.com/photoshop_family/categories/photoshop_family_lightroom_cc