How do I get my WordPress to generate thumbnails?

Hello,

Recently I changed my hosting provider for another one.

When I upload my image to WordPress, WP is unable to generate the thumbnails and only sends an "HTTP Error", which is close to useless.

So, the image successfully uploads but the thumbnails are not generating. I have tried with some .htaccess rules, reinstalling WordPress, and setting some variables in the php.ini, with no results.

Is there a chance you can help me out with this problem?

Thanks in advance :smiley:.