I discovered that if you open lmms by root (sudo lmms) you can save the crashed proyect as a new version an then you can still editing and working on it by open lmms in the traditional way.
I think that must be some issue about access denied or something like that. In my case, the crash happen when I try to work in old projects saved from another Linux systems like Kubuntu. Now in my L Mint maybe there no exist the same directories.
I hope this can help to someone.