Sorry, Ubuntu 15.10 has experienced an internal error

A few days ago, i had this error on my lubuntu 15.10 wily werewolf, the error is related with PCManFM which is the file manager on lubuntu.

The error says, 'Sorry, Ubuntu 15.10 has experienced an internal error' it says ubuntu not lubuntu, despite the logo is lubuntu logo.

When i show the detail of the error, it says that the file manager (PCManFM) is crash, causing the error message appear.

It seems that PCManFM cannot located config file or something, Error: [Errno 2] No such file or directory: '/etc/xdg/pcmanfm/lubuntu/pcmanfm.conf'.

I had no idea why this is happening, anyone had the same problem? please comment down below if you know something.