Playback slow even when fully rendered

[Samantha26790971vjt2]

I'm working on an AE file that's been in progress for over a year and have had no issues until the last few weeks. Recently when I start the playback it's VERY slow and really distorts the audio, even when it has been fully rendered. What would be causing this all of the sudden?

[ToolfarmJP]

You check out the read/write speed of disk where you save the files. Is it fast enough?