When a quote is sent to a customer, the associated supplier and cost price are set to read-only mode. This restriction is in place to ensure the integrity of the quote during the transaction process.
If you attempt to change the supplier for a sent quote, you may encounter an error message stating: "Access Forbidden: Unfortunately, you do not have access to this page." This indicates that you do not have the necessary permissions to make that change.
To resolve this issue, you will need to retract the quote first. Once the quote has been successfully retracted, you can then proceed to change the supplier as needed.
Following this process will allow you to manage your quotes effectively without running into access issues.