I attempted to edit the IDF file by editing the ShadowCalculation object accordingly:

ShadowCalculation,
  PixelCounting, !- Shading Calculation Method
  Periodic, !- Shading Calculation Update Frequency Method
  20, !- Shading Calculation Update Frequency
  15000, !- Maximum Figures in Shadow Overlap Calculations
  SutherlandHodgman, !- Polygon Clipping Algorithm
  512; !- Pixel Counting Resolution

However, when I save the IDF file and try to import it into OpenStudio, I receive the following error:

"File is not valid to draft strictness. Check that IDF is of correct version and that all fields are valid against Energy+.idd.


The collection is INVALID at strictness level 'Draft', because of the errors:
Field level data error of type DataType .
Error is in an object of type 'ShadowCalculation', named '', in field 0.
Additional information about the error type: field-level data is of an incorrect type.
Field level data error of type NumericBound .
Error is in an object of type 'ShadowCalculation', named '', in field 2.
Additional information about the error type: numeric data violates a min or max bound."

Do you have any suggestions?

Thank you, Cullen