Images not imported

Hello!

I try to import content from Joomla, seems that all posts are imported but for images it gives an error like it`s not found. But when looking source code, the image url is correct. When looking joomla folders, images are in subfolder (images/subfolder) Shall I modify some plugin file accordingly? Would it be possible also to import all posts to custom post type in wordpress?
Thank you for your help!