I have not been using the program for some time, despite having purchased version 3. I tried to reopen an old file made with version 2, but I get the error “The selected file is not recognised timeline format”.
What extension does your file have?
The latest .aeonzip format of Aeon Timeline 2 is read by Aeon Timeline 3 without any problems.
For the older .aeonxml format I can’t tell. In this case you could try to open the file first with the latest version of Aeon 2 and save it in .aeonzip format.