Impossible to load pictures anymore!

i don’t know what happened: sudddenly, I can not load any picture anymore.
I’ve the following message when trying to load a JPG 197KB file:

“File is empty. Please upload something more substantial. This error could also be caused by uploads being disabled in your php.ini or by post_max_size being defined as smaller than upload_max_filesize in php.ini.”

I contacted Hostgastor and they told me everything was ok on their side and that the max. size was not reach.

Could you please help me with that?
Thanks