First sign of this bug was when I saved and quit my world back to the menu. It took about 2 minutes to save and quit. I then noticed that the world size had increased from around 127MB to 879.4MB. I was shocked. So I went to see what had gone on the the worlds directory.

Upon inspection the db folder size came up as around 753MB. I opened the folder and then I see the file causing the issue. It was because the .log file had blown up to around 752MB.

Any ideas what could have caused this or is it a bug?