If you are having trouble opening and/or saving your models on a Mac with version 10.10.5 (Yosemite+), don’t trash the LDD software, just yet! Here are a couple of solutions.
For some unknown reason sometimes certain LDD files will not ope from the software. The solution: open the file directly from LEGO Creations folder - Models.
Sometimes a file might not save (that’s frustrating). If you are experiencing this try saving the file first, before designing.
By the way, lego.com has removed LDD for their website. However, I Googled it and it appeared @ http://ldd.lego.com/en-us/download/
Could this mean LEGO plans to do away with LDD? OMG, I hope not! I find it a useful tool for my own models and as an instructor of LEGO Tech & Robotics Engineering it is excellent for teaching.
Perhaps they are working on a new version…