IPN ERROR:: Could not find stored session {} in DB;

[lruskauff]

I installed Paypal Express on 7/31. 4 transactions have been processed, 3 orders and 1 refund. Two of them were recorded under Customers: Paypal IPN in the admin. The other two sent error messages. I have debug turned on. I did get all 3 payments and 3 orders were recorded, as was the refund.

Error for 1 file:

Aug 01 2015 13:39 -- IPN PROCESSING INITIATED.
*** Originating IP: 173.0.81.1 notify.paypal.com
***
Browser/User Agent: PayPal IPN ( https://www.paypal.com/ipn )

Aug 01 2015 13:39 --
IPN ERROR :: Could not find stored session {} in DB;
thus cannot validate or re-create session as a transaction awaiting
PayPal Website Payments Standard confirmation initiated by this store.
Might be an Express Checkout or eBay transaction or some other action that triggers PayPal IPN notifications.


Aug 01 2015 13:39 --

IPN ERROR :: No saved Website Payments Standard session data available.
Must be an Express Checkout or Direct Pay transaction.
Could be a test notification,
or the incoming IPN notification is not actually a bonafide PayPal transaction.


NOTE: It is likely that all the following log content is meaningless or irrelevant.

but even tho they said meaningless, this error was at the end of the debug file(a bunch more if I need to include it):

IPN NOTICE :: Could not find matched txn_id record in DB. Therefore is new to us.

Aug 02 2015 15:58 -- Breakpoint: 4 - Details: txn_type=unique ordersID = 0 IPN_id=0

Relevant data from POST:
txn_type = unique
parent_txn_id = None
txn_id = xxxxxxxxxxxxxxxxxx

Aug 02 2015 15:58 -- IPN ERROR :: Could not find stored session {} in DB; thus cannot validate or re-create session as a transaction awaiting PayPa
l Website Payments Standard confirmation initiated by this store. Might be an Express Checkout or eBay transaction or some other action that
triggers PayPal IPN notifications.

Aug 02 2015 15:58 -- IPN ERROR :: No pending Website Payments Standard session data available. Might be a duplicate transaction already
entered via PDT.

Aug 02 2015 15:58 -- NOTICE: IPN Processing Aborted due to missing matching transaction data, as per earlier debug message. P
erhaps this transaction was already entered via PDT? Thus there is no need to process this incoming IPN notification.

The error was the same for the other transaction. I didn't include all of the middle information but will if necessary.

The one that recorded the IPN correctly was a "Mobile Express Checkout". The refund that I did was for this one and also recorded.
The two that didn't were "Express Checkout .

The only other difference that I see, is that when I look at the details in Paypal, the two that failed have a blank after the tax line and the one that went through has 0.00. Like:

This is one that gave error:
Item Total:
$19.99 USD
Sales Tax:

Shipping:
$3.54 USD
Seller discount or charges:
$0.00 USD

This is one that didn't give an error:
Order Description:
Shopping Cart
Item Total:
$197.15 USD
Sales Tax:
$0.00 USD
Shipping:
$0.00 USD
Handling:
$0.00 USD
Seller discount or charges:
$0.00 USD

Since it had that reference to tax_id being missing in the database, it might be relevant.

One last thing, all 3 have a tax of $0.00 in zencart.

So is there a problem and if so, where do I look next? Thank you in advance.

lruskauff

additional info:
I originally used Paypal Standard with Authorize AIM and free order. After upgrading to 1.5.4 I decided to switch to express so I turned off Standard and turned on express. I could not get it to work at the time, so I turned off all of my Payment modules and added them back one at a time. I added AIM and free first, and have been using them for about a month with no problems. Added Express on 7/31. Sort order: 1 Aim, 2 Express, and 5: Free Order.