actor component default data loss.

Today when i loaded my project, default data from one of my actor component just disappeared.
Data was just multiple arrays of anim montages set as variables ; all arrays are empty now.
There was no crash yesterday when i stopped working. Didn’t do anything special.
Is it a common problem?
is there any way to recover lost stuff?
must i force myself to use datatables&co in ANY custom config?
am i crazy?