illogicomio

I guys all, I'm Andrea, new here and new to cura and 3D printing in general. My problem is on my MacBook, I downloaded the beta version of cura, tried to import a obj file to do some testing but it every times it pops up a message saying that cura has failed import that file, I tried different files same problem, I tried same cura version on an iMac (with sierra) and all worked fine. The MacBook is an old one from late 2008 with Yosemite on it. Did someone had the same issue by any chance? Thanks in advance for your help