@Trang_Dang1 thanks for sending the CSV file. It appears that the issue is the way in which Asana has chosen to identify when there are multiple “blocked by” dependencies for a task. They use the comma as a delimiter for this so that is why you are unable to select the Dependents column as the one defining how dependencies will be mapped due to the error:
In your case, for the “Apply for routine” task Asana thinks there are 3 dependencies:
- Implement the trial
- feedback
- revise
instead of just the one dependency of: Implement the trial, feedback, revise
I have posted this issue here: Unable to map dependencies using the CSV Importer when the "blocked by" dependency includes a *comma* in the Task Name
if you replace your commas with a semicolon or hyphen, for the time being, in your CSV then everything maps perfectly! I do hope this is addressed because I personally think commas are more common when starting actionable task names in Asana. IMO a semicolon would be more appropriate delimiter (or some other uncommon character)