I have seen a specific Crystal Reports failure with three different customers in the past few months and several other times before that. It happens whenever Crystal has to run “too many” recurring subreports instances. This results in a slow cascading failure. The most obvious symptom is the status bar along the bottom of the screen.  It starts to print new text over the existing text like this:

This gets worse for a few seconds and eventually Crystal locks up and has to be shut down in the task manager. Sometimes there is no error message and it just freezes, sometimes a message says “A required resource is unavailable”.  But the one consistent symptom is the status bar that overlaps while the subreports are running.

It is also an inconsistent problem, in that the same report might might fail earlier or later, and will sometimes run without an issue. You can stop the report when it is part way done with no problem, but once the status bar starts to print overlapped text, there is little you can do.

(update 6/8/17) There is one possible solution mentioned here.

I also found a few forum threads that discuss similar problems, but the solutions are all over the place.  The last resort solution is replacing the subreports with SQL Commands or complex arrays.  If you are experiencing the same issue or have any insight, please let me know.

Here are the threads I have found that might be related.

https://archive.sap.com/discussions/thread/1824033

https://archive.sap.com/discussions/thread/1899387

https://apps.support.sap.com/sap/support/knowledge/public/en/1768189