Revit cannot complete the external command unhandled exception Object not set to an instance of an Object

Unable to open cal

All data was lost in a calculation. Calc file is empty when opened. All Data Lost HydraCALC

When calculating a system with a CITY + PUMP supply, after editing the pump flow (ie trial and error to size a pump), you get a result with a 0.00 safety margin. Upon further review, the calculation's CITY supply has been changed. n/a HydraCALC

HydraCALC gets the Blue Screen of Death same issue if picking help and about in the following Apps HydraCALC HydraCALC Sizer HydraVIEW HydraLIST

There is a Buttons.MDB file from a version of the software that is newer than the SLD_Prog.exe that is being used. 326 50.20 or older

ID PIECE HOLDER was used improperly. C++ Runtime Library n/a 50.21

1. Only Misc items in list, Misc items have only quantity and description, no part numbers. Total Weight is turned on as a report, printing to cover sheet. SldReports MFC any?

Windows 10 setting. It will change your default printer setting based on usage. small text

windows 10 file open elevation

You could get this error back as far as Vista, it is another UAC type error

On a new install on a new computer any file Open operation works on any new file created. 'The Requested Operation Requires Elevation' error appears on any file Open command if the file comes from another computer the ownership of the file or folder needs to be added for this user.