i was using 3.6.9 but today i installed 3.6.10 after installing it's ask me about revert then i did revert after revert my style footer and header images are missing
Did you edit the header/footer originally for a modification you installed? Just go find the modification thread and read the installation instructions again and I'm sure the template edits will be explained there.
(Or, if you have a test board setup, look at the templates there.)