You got the header option working again, but did you really do it correctly by fiddling with the database? If you look at the debug message, you can see a filedir/f4/45/whatthefileiscalled.
This file is missing from your moodledata folder, likely because of a botched migration. I would have packed up your original moodledata folder and attempted to upload the whole folder again. If all files transfer correctly, you should never have these errors.
