I have used Thunderbird for many years. I have configured it so that the profile is stored in Documents so that it is backed up at the same time as all other documents. I have a program which compares folders on networked computers and allows the folder files to be sync'd. Again used it for years. I was updated to V102.13.1 (64bit) on all my computers Except one which was an old Samsung Netbook which was 32 bit. I decided to update to V115.0.1 and downloaded the 64 and 32 bit versions, I decided to try the upgrade first on the Netbook as it was the least critical machine without risking my main and backup machines, both 64 bit. I first ensured that the current latest profile was saved and on all 3 machines. The profile saved on a 64 bit machine has always worked on the 32 bit machine. I only use Local Folders for email storage with several sub folders. I upgraded the Netbook to V115 however on opening the program I was unable to see any of my stored emails. I did note however that Thunderbird did download new emails from the server and displayed the number of new emails (urrently 14) but none of the headers were displayed. So I can not rtead any existing emails or unread new emails. I have again checked that the contents size of folders have changed. after doingthe mail update so the messages would seem to be downloaded but not displayed to enable them to be read. I am very reluctant to upgrade any of my main 64 bit machines incase I have a sililar problem as I am currently away from home. I am open to any ideas as to the reason for this problem or confirmation that 64 bit Version 102 profiles do not work in V115 32 vit machines. Thanks in advance Alan