Error:  Current Quantity value is All. The recommended value is Packing slip. Do you want to apply the recommended value?

Fix issue when invoicing where users have to always change to All

Go System administration->Users

Find the users

Edit the user

Click options button at top.

Go to users  usage data.

In the element name column, search for "SalesEditLinesForm_invoice"

Go to file menu and select delete

Have the users  go post an invoice

They will be prompted with the following

Select the option “Don’t ask again”

Next click the “No” option