Katamaze - Billing Extension issue with Stripe gateway

[Bodoh]

Hello all,

 I'm using Katamaze - Billing Extension but I'm getting into an issue when trying to test the order flow after the payment.

 Details:
 - WHMCS version 8.7.3
 - Billing Extension addon latest version 2.2.181
 - Stripe with "Test data" mode enabled.

 Error after completing a payment (tried with a new credit card and also with the same saved):

TypeError: Argument 2 passed to BillingExtension\BillingExtension_Admin\Hook::Warnings() must be of the type string or null, array given, called in /home/user/mysite/modules/addons/BillingExtension/core/BillingExtension_Admin/Hook.php on line 4397 and defined in /home/user/mysite/modules/addons/BillingExtension/core/BillingExtension_Admin/Hook.php:3755
Stack trace:
#0 /home/user/mysite/modules/addons/BillingExtension/core/BillingExtension_Admin/Hook.php(4397): BillingExtension\BillingExtension_Admin\Hook->Warnings('gap', Array, 'Automatic')
#1 /home/user/mysite/modules/addons/BillingExtension/hooks.php(687): BillingExtension\BillingExtension_Admin\Hook->SequentialNumbering('set', 'Invoice', 35, false)
#2 /home/user/mysite/vendor/whmcs/whmcs-foundation/lib/Hook/Manager.php(0): BillingExtension_InvoicePaidPreEmail(Array)
#3 /home/user/mysite/vendor/illuminate/support/Facades/Facade.php(261): WHMCS\Hook\Manager->run('InvoicePaidPreE...', Array, false)
#4 /home/user/mysite/includes/functions.php(0): Illuminate\Support\Facades\Facade::__callStatic('run', Array)
#5 /home/user/mysite/includes/invoicefunctions.php(0): run_hook('InvoicePaidPreE...', Array)
#6 /home/user/mysite/vendor/whmcs/whmcs-foundation/lib/Billing/Invoice.php(0): processPaidInvoice(35, false, Object(WHMCS\Carbon))
#7 /home/user/mysite/cart.php(0): WHMCS\Billing\Invoice->addPayment('19.90', 'txn_3NXSgIDxLmL...', '0.85', 'stripe')
#8 {main}

 Did anyone hit the same error? Or any ideas here?

I can't look into "hook.php" file as is IonCube coded, so I don't know what is trying to do. 

 

Thanks in advance!
Bogdan

[WGS]

open the ticket to them.

[Bodoh]

Unfortunately they don’t offer support anymore, only at a premium rate of 899€ /month. 
 

 “End of Free Customer Support

Given the complexity of modules and the current state of WHMCS, providing support free of charge isn't possible without increasing prices which is something most customers don't want. We know from numerous feedback that low prices is what the vast majority of you want“