Our organization has got a project where we need to migrate a Learning Management System built in Adobe Flash to HTML 5. I know there are number of converter available to do the same, however the flash files seems to be too old. I tried with older version even Macromedia flash 2004 but it always failed to load. However when I tried Adobe Animate CC, I able to load the flash file successfully and convert it but it looks it has not migrated action script file (in fact it deleted the file while migrating). The action script file are originally in version 2.0.
I need to know what precautions should we take while migrating to HTML5 and what are the best methodologies. In addition to that, what tools would be helpful for this task? How much manual work is involved?