JEdit plugin error while loading Isabelle

Question

I am working with a Windows 10 device and after some work with Isabelle I get the following error:

The following plugin could not be loaded:

C:\Users\PC\Desktop\Isabelle2018\src\Tools\jEdit\dist\jars\Isabelle-jEdit.jar:

Cannot start:

*** [line 1 of "preferences"] error: bad input

I note this problem appears in this version and in a previous Windows 8 version when not switching off properly the machine.

Answer 1

In the Isabelle list I got an answer to this problem:

The error indicates that the $ISABELLE_HOME_USER/etc/preferences file is in a bad state: the file is written each time Isabelle/jEdit shuts down, and switching off the computer in the middle might have corrupted it.

You can try to repair or delete that file. The location of $ISABELLE_HOME_USER on Windows is usually something like C:\Users\my_name.isabelle\Isabelle2018.

I think this problem may be encountered by other people in the community and this answer may save some time to them.