In my case the problem was in the Dispatch Address (the send-from address), it was set to my Parcel Locker. When I changed it to normal street address it went through. Hoping this helps somebody out there.

 Sendle doesn't send to PO boxes. Could that be your issue? 

Colleagues, Success at last at overcoming the dreaded Sendle “Something went wrong and we weren't able to generate the label”!!  In addition to the receiver’s address being valid for Sendle, it would appear that your address as the sender also has to be valid AND deliverable to by Sendle (I assume in case they need to return the item as undeliverable).  I was using a PO Box as origin for sending from and receiving items.  I have updated my Primary Address from the PO Box to my physical home address (My eBay > Account > Addresses > Return Address). I had to do this for all 5 of the addresses I had in eBay (Registration Address, Postage Address, Dispatch Address, Return Address and Payment and Pickup).  I was then able to generate a Sendle Label.  I am now in the process of switching all my addresses back until I next need to generate another Sendle Label.  Thanks to sqleonhart who tipped us off about the Dispatch Address.

This happens for Sendle where the recipient has a PO Box. Sendle don't send to PO boxes, only physical addresses. The ebay warning should be clearer on this.

In my case the purchasers suburb was not put in the correct section.

In the section that said "CITY" the purchaser had put their state and not suburb. The city and postcode did not match so the delivery address could not be verified by AP or Sendle and would not print label.

Therefore:

CITY: This is the suburb

POSTCODE: purchasers postcode should match the city (suburb)

I have found the problem and solution.

Ebay has 5 different addresses for you.

You need to set them all correctly, I only noticed because 1 was showing up as an old P.O. Box while everything else is fine.

Under Account Settings, go to Addresses.

Check all of them. I had to fill 2 in, and change the P.O Box to my street address and instantly the postage labels worked.

Simply an update for those interested....the eBay delivering name page actually won't process for me following 2 days, gives a similar blunder message, so nothing was fixed by eBay.

But....the mail center (was really the AustPost LPO counter at my nearby newsagent) acknowledged the snap and gather address no issues so you have a choice of paying for postage at AustPost for snap and gather addressed items....not bound to eBay transporting names. Somewhat more 'manual-matic' which is OK for the odd thing to post.

Likewise the post expense was a similar cost as eBay and I got a following number which I entered physically for the purchaser.

Just an update for those interested....the eBay conveying name page really won't process for me following 2 days, gives a comparative bumble message, so nothing was fixed by eBay.

But....the mail focus (was actually the AustPost LPO counter at my close by newsagent) recognized the snap and assemble address no issues so you have a decision of paying for postage at AustPost for snap and accumulate addressed items....not bound to eBay moving names. To some degree more 'manual-matic' which is OK for the odd thing to post.

Moreover the post cost was a comparative expense as eBay and I got an after number which I entered truly for the buyer.