Sorry for my english.
I have exactly the same problem.
But i understood that this problem come each time i restart my computer.
If i don't restart my computer, there is no problem.
I f i restart my computer, spare parameter explode or are deleted .. and i need to take a backup.
If you want, Juanjgon, i can send you my file.
And perhaps, if you restart your computer, you will find this problem!?!
I'm really stressed and i need to animate a mix material.. but each day , when i restart my computer , all is erased or crash.
Please, can you help me?