Report error An error occurred while running the report.

[Dane Dormio]

I am running the latest version of GNUcash (2.6.18) on Windows 10.  When I
choose report type the default report for that type works fine, but when I
try to customize the report I get the following error: "Report error An
error occurred while running the report."  Currently I am trying to run an
expense report over a ten day period for a single expense category and am
getting this error.  What can I do to fix it?

Thanks