Trait data histogram not showing for select species

[CorinnaPaeper]

In some instances, the trait data histogram gives an error when a single species is selected. For example, morph_SVL is selected as the trait with the histogram displaying correctly when an outer node is selected. 

Selecting xenopus results in an error message in the histogram section, however, the data-point in the tree has been assigned the correct value from the attached spreadsheet.