Things I have tried. I tried turning off the internet on my Macbook. I tried installing the same version that's on my desktop on my Macbook. I tried a super old version 60. I tried deleting all profiles then creating a brand new one. I tried installing on a 2nd windows desktop computer and the same result as the Macbook. I tried copying via a flash drive and via a usb hard drive. I tried using the export function but it only works up to 2gb. My profile is 2.7gb.

One possibility would be to copy the message files from the Windows profile folder (e.g., Mail\<POPaccountname>inbox to the Mail\Local Folders folder on the MAC profile and restart Thunderbird.

Thank You david. I actually was trying to copy an old profile (the wrong one). Now that I have that figured out I'm still having mostly the same issue. I've figured out that the emails I want to access are under the ImapMail folder inside the profile. Inside Thunderbird I finally can see the local folders but just trash and outbox are there. There's no Inbox. I thought I saw that erasing the .msf files in there might rebuild the local folders...

Okay, copy the folders in Imapmail to Local folders and restart Thunderbird.

david thanks for your help! That didn't work but it helped me to figure out what did. I put the main inbox file that was inside the ImapMail folder directly into the local folder. Yay! So happy it works finally! Thanks again!

You are welcome. :)