I cannot generate a DHL Label or send out a “Sent E-Mail” to customers

Hallo,

Thank you for fixing the plugin. However now when I try to generate a DHL label that I add to the product packaging, I get the message, “Cannot convert string “true” to a double” (see screen shot in attachment). Because of this I cannot send out packages to customers who are waiting. Please may you help me out.

Thanks in advance!

P.S. I generate the DHL under Woocommerce > Orders > (pick out an order) (see screen shot in attachment)