When changing pipe diameter, with pipe annotations Length (3D) and Diameter created, results in the error "index was outside the bounds of the array."
This issue has been logged as defect report number 389818 and is resolved starting with the CONNECT Edition. You can find information about upgrading here:
Downloading OpenFlows (Haestad) Software
If "Use 3D Length?" is checked (Tools>Options>Hydraulic Model), then the pipe attribute "Length" is equal to "Length (3D)". Therefore, the annotation "Length" can be used in place of "Length (3D)".
Large number of output files (.OUT, .RPC) being saved OR System.IndexOutOfRangeException: Index was outside the bounds of the array error message