I have also had several consecutive APRX files fail on me. I think the
reason may be related to a particular gazetteer file that I enable for
searching using the Locate tool. Since disabling this layer from the locate
tool after use, it appears to have stopped, but more testing certainly
required. I still need to submit case to Tech Support.
Did you do something similar?
I am running Pro 1.3.1 on Windows 7.