I hope you are not using \ or / in your folder names. Always a bad idea as that is the operating systems file system folder delineator, one for Linux/Unix the other for Windows. If there is a bug in the folder handling and escaping, that is almost guaranteed to find it.

But I really do not follow what you did or why.

so I HAD, 2 seperate folders. 2 folders = /primary-2023 & /2023-emails

Where did you have these folders?

I copied them to /primary-2024 & 2024-emails respectivatly

again were were they stored? where did you do this, even how did you do this.

I ran thunderbird -P and deleted 2023 and created 2024.

Why would you delete what you had before you determined that your new profile was actually working as expected. Why you would create a new profile for a calendar year I have no idea. I have been using the same Thunderbird profile for a decade. I use folders in the profile to yearly archives.

Calander was working now it is blank

You deleted the profile that contained the calendar, so I am completely lost here.

But I really do not follow what you did or why.

   so I HAD, 2 seperate folders. 2 folders = /primary-2023 & /2023-emails

Q from Matt = Where did you have these folders?

   I copied them to /primary-2024 & 2024-emails respectivatly 

Q From Matt = again were were they stored? where did you do this, even how did you do this.

    Calander was working now it is blank

A- I found the 2024.ics file in the wrong location, and corrected it.

A from Charles = My Full folder names are /media/username/Home/username/2024-Dragon/Essentials/Primary-2024 [Profile folder] (Primarily or MAIN Used emails=8) /media/username//Home/username/2024-Dragon/Essentials/Secondary-2024 [Profile folder] (secondary Profile of specific emails=12) /media/username//Home/username/2024-Dragon/Essentials/2024-Primary-Emails [Email Accounts folder] (Like the default sub-folder "mail" in the Profile folder.) I made this change it 2019 and moved the actual email accounts STORAGE to a separate (Encrypted) YEARLY Sub-Folder. I HAD and HAVE my Reasons, see below.

   I ran thunderbird -P and deleted 2023 and created 2024. 

A from Matt = Why would you delete what you had before you determined that your new profile was actually working as expected. Why you would create a new profile for a calendar year I have no idea. I have been using the same Thunderbird profile for a decade. A from Matt = I use folders in the profile to yearly archives. A from Charles = I reinstated the 2023 Primary profile, just to get my emails back.... BUT I still need to move it to a 2024 yearly folder... SO I KNOW where they are.

Q for Matt = And How have you done this "Yearly Archives" retaining all email accounts and sub-folder info (Inbox, Sent) ????? I have spent years trying different ADD-ONS, to no avail.

Q to Matt If you have been using the same "email" default ".thunderbird" foled for many years, how BIG is it. I Changed the structure of my emails as I was sick to death of waiting 5-7 minutes for 40+ Gigabyte of email files to open into memory. As emails as in all the joke attachments, other important attached documents, and the fact most people I communicate with have the A4-A5 page sized signatures with Images, and fancy layouts, that multiple every-time I reply and they reply.

A from Charles = YES. I made an error. As in the previous 5 years moving Profile folder and actual email data folders has worked. TB has changed something, and it didn't work this year. TB actually found 2 year old email data (from god knows where.) I DO this so I could find email accounts that become compromised (spam or abused). I am able to compress the emails, deleted the account and files. Then I create a different account(s) as needed. It is also a security measure as my emails are not where "everyone" else expects them to be.

So do you understand that I have multiple Profiles, and multiple separate "email storage" folders. At the end of the year, I can compress emails, BACK THEM UP to 3 or 4 locations. I also, after a lot of mucking around Integrate, them in to another Profile titled 2020-all. This has all the years emails under different E-Mail Years sub-folders. This Profile takes 4-5 minutes to load. FYI Some of us can't afford the latest, flashy, fastest, 200core CPU 256Gig Ram PC upgrade every year. We make do with what we have. Q for Matt..... Do you consider this or the fact that all the "back-up" ADD-ONS don't work. The last 4-Star backup did actually back-up all my emails.... INTO ONE SINGLE Sub-Folder. Completely useless. Microsoft Outlook uses a "file" that you can compress emails on an annual Basis, and then just move it, and created a new "file". If you need to access older year emails, you can simply load that file as <Year-Name>. It may take minutes to load but it doesn't affect your current emails, and you can UN-LOAD it when done. TB still has no equal to this. Above is my attempt.

A- I have followed the advice from this forum that you copy profile to new location (similar to move to new pc), but it is like you expect us to have everything in the /Home/.thunderbird/ folder. We can no longer change this default folder. Same as all the "Color Add-Ons that Don't Work either" We must put up with basic colors unless you want to D/L some Theme. Most themes are not as advertised. What I do is also easier for Daily & Monthly backups as I know the direct Path to the Emails. I can restore anything that becomes corrupted. Thanks Matt for His Reply.