Server Fix - (I think something with curl and PHP)

PLEASE READ !!! Hi, i have a little server issue. I bought / rent a new server and moved a websoftware for invoices and estimates from the old to the new server. (Old server still online) The Server works fine on the new server, but when i try to convert a estimate or invoice to a pdf, the pdf dont get images anymore. The images are not loading in the pdf or when the pdf is created. Its not an develop error from the system, because exactly the same works on my old server which is also a linux server. 2 other guys said me, that it is something with curl and GD library also ad fopen, url_fope. I use Virtualmin / Webmin on my new Server. curl and php gd is installed, but still dont work. I attached 2 screenshots. The one is how it must looks after the convert to pdf, the other is, what i get here on my new server after convert to pdf. (How you can see, no images...) The PDF Convert engine is "mPDF" if its important. The Software which i use is: [login to view URL]