There are a few problems which can arise when running Lertap.
The topics immediately following address the two most common problems: macro security, and matters which relate to running Excel in "compatibility mode". Both of these problems can be resolved relatively easily.
A third problem may arise when the Windows Region and Language setting is set to a format where the decimal separator is a comma instead of a full stop. For example, if a test mean is formatted as 50,35 instead of 50.35, some of Lertap's options may fail. The "Res. Charts" option is one; it will produce a "Whoops" error message.
A more complete discussion of issues associated with the Excel 2007, Excel 2010, and Excel 2013 versions of Lertap may be seen at the following URL:
Page forward to take in the macro security and compatibility mode topics.