The deals have rotted with respect to its date of creation. Input a higher value (even in thousands) to avoid this occurrence. Navigate to Admin settings > pipelines > select the desired pipeline and increase the rotting age.
Ensure that the .CSV or XLSX file has the proper header with no special characters.
The related contacts column should have the email id of the contact to be associated. You can have multiple email ids separated by semicolon(;) in the related contacts column to associate the deal with multiple related contacts.
The Account Name column should have the exact name of the account for the association to happen.
Pipelines with corresponding stages are created in Freshsales. If custom pipelines are not created, all deals will get added to the default pipeline.
All the required fields should be mapped to avoid errors.
While editing the deal stages, you will have to edit them one by one. Edit a deal stage, save it and then go for the next one as a unique ID will be generated for each deal stage and editing the deal stages all at once will throw this error.