This error occurs when the
state.dat JSON file is malformed.
The way to work around this error is to delete the file or manually delete the lines that do not conform to the JSON syntax and restart the processes.
Known reasons why
state.dat may be malformed are:
Both cases can cause either the
scanner or the
generator not to
finish writing proper JSON lines to the file, since this operation is not
This error does not happen in the next scanner version because is using a database that support atomic operations.