If you upgraded from an older version of Hopper to a more recent one, you probably noticed that the callstacks are gone from the Hopper logs.
We made them optional for two reasons:
1. Printing out callstacks slowed down the run significantly
2. They did not provide a lot of value, because the callstacks were printed out at 5 minute intervals and not at the points of interest
If you feel that you can benefit from these callstacks you can turn them back on by passing /d to Hopper.exe. To pass a switch to hopper you can use the debugger's target window. If you don't have a debugger attached you can create a link file that passes the switch to Hopper.exe. MSDN has instructions on how to create link files here