In OpenStudio 1.11.0, when adding the "set_output_table_to_IP_units" measure in the Measures tab, it seems to hose some of the OpenStudio results. For example, the HVAC Load Profiles disappear. The following message also appears:
[openstudio.energyplus.SqlFile] <0> Tabular results were not found, trying to calculate it ourselves
Once removing that measure from the Measures tab, the OpenStudio results seem to turn out OK again. I thought you might want to know in case anyone maintains this measure.
The EnergyPlus results themselves seem to be fine either way, i.e. the unit conversion appears to work, at leas for the two sample data points I compared.