This article describes integration best practices and recommendation from the OnePlan team regarding the Smartsheet with OnePlan integration.
This integration focuses on Sheets in Smartsheet becoming Plans in OnePlan, and the rows within Smartsheet will appear as Schedules items in the OnePlan Work Plan. The reverse is also possible, Plans within OnePlan will become a sheet in Smartsheet, and any Scheduled items in OnePlan Work Plan will become a row item in Smartsheet.
Unfortunately, Smartsheet does not allow updates to the Finish Date on Project type sheets currently. The finish date is automatically updated by the duration and start dates defined beforehand.
To prevent this error from occurring in the future, please either change the field mapping for Finish date to only go from Smartsheet to OnePlan or remove the field mapping completely.