Version 6.6.42 was a release candidate version of the software that did not make a full release due to a few issues reported back to us. These were fixed in the 6.6.46 release candidate which has now been upgraded to a full release.
Can you try this version and let us know if the issue still exists. Go to http://www.picotech.com/software.html and select 4226 at Step1 and the software at Step2
The team have found an issue with trying to save a file when there is no data on the display, and this will be included in a future release. Your macro creates this issue so we believe it is the reason for your crash.