Please post the contents of the fml-client-latest.log file inside the logs folder inside your .minecraft folder to some pastebin site and link to the post here.
Note that this log will only contain information on the last time you started Minecraft, not any previous runs.
So, do that after trying to recover the replay. That log may already contain enough info for us to fix the recovery issue.
fml-client-latest.log file inside the logs folder inside your .minecraft folder to some pastebin site and link to the post here.