Hello guys, I am writing to ask you about this error that is happening to me.
I have a site with version 1.9.0.1 of Magento in which I have a large number of products, the point is that several products were without images overnight, these products already had their image configured at the time.

I've been looking about this but there is little that comes out and nothing similar to what has happened to me.

Do you have any antecedents or something that can help me solve it?
Thank you very much in advance.
Greetings.