Already deleted it, but only thing the window said anywhere was line numbers and main folder. I am on OS X.
But I reproduced the problem after checking if I have the last version. This is the error I get:
As you can see, it only gives out the main folder, not the hundreds of chapters inside it. So, the full path of the corrupted file is missing. If there are multiple chapters inside the main folder, you will face quite a chore to find the broken file.
What I did was corrupting a file by deleting first three lines with Vim and putting it inside a 100 chapter manga. But even if I prepare only two chapters, problem remains.