Order error

HI,

I just got the plugin and when i do an order it shows an error:

Unexpected token < in JSON at position 0

Warning: call_user_func_array() expects parameter 1 to be a valid callback, array must have exactly two members in /home/souffle/public_html/wp-includes/class-wp-hook.php on line 288
{“id”:76461,”parent_id”:0,”number”:”76461″,”order_key”:”wc_order_9E6d6KtLzWc5f”,”created_via”:”rest-api”,”version”:”3.5.4″,”status”:”completed”,”currency”:”CAD”,”date_created”:”2019-02-15T10:30:45″,”date_created_gmt”:”2019-02-15T15:30:45″,”date_modified”:”2019-02-15T10:30:46″,”date_modified_gmt”:”2019-02-15T15:30:46″,”discount_total”:”0.00″,”discount_tax”:”0.00″,”shipping_total”:”0.00″,”shipping_tax”:”0.00″,”cart_tax”:”0.15″,”total”:”1.15″,”total_tax”:”0.15″,”prices_include_tax”:false,”customer_id”:0,”customer_ip_address”:””,”customer_user_agent”:””,”customer_note”:””,”billing”:{“first_name”:””,”last_name”:””,”company”:””,”address_1″:””,”address_2″:””,”city”:””,”state”:””,”postcode”:””,”country”:””,”email”:””,”phone”:””},”shipping”:{“first_name”:””,”last_name”:””,”company”:””,”address_1″:””,”address_2″:””,”city”:””,”state”:””,”postcode”:””,”country”:””},”payment_method”:”pos_cash”,”payment_method_title”:”Esp\u00e8ce”,”transaction_id”:””,”date_paid”:”2019-02-15T10:30:47″,”date_paid_gmt”:”2019-02-15T15:30:47″,”date_completed”:”2019-02-15T10:30:47″,”date_completed_gmt”:”2019-02-15T15:30:47″,”cart_hash”:””,”meta_data”:[{“id”:1007860,”key”:”_pos”,”value”:”1″},{“id”:1007861,”key”:”_pos_user”,”value”:”1″},{“id”:1007862,”key”:”_pos_user_name”,”value”:”Michel Petit”},{“id”:1007863,”key”:”_pos_cash_amount_tendered”,”value”:”2″},{“id”:1007864,”key”:”_pos_cash_change”,”value”:”0.8502″},{“id”:1007869,”key”:”_pos_payment_result”,”value”:”success”},{“id”:1007870,”key”:”_pos_payment_message”,”value”:”Montant soumit: $<\/span> 2.00<\/span>
Modifier: $<\/span> 0.85<\/span>”}],”line_items”:[{“id”:8028,”name”:”test1″,”product_id”:76455,”variation_id”:0,”quantity”:1,”tax_class”:””,”subtotal”:”1.00″,”subtotal_tax”:”0.15″,”total”:”1.00″,”total_tax”:”0.15″,”taxes”:[{“id”:13,”total”:”0.05″,”subtotal”:”0.05″},{“id”:14,”total”:”0.0997″,”subtotal”:”0.0997″}],”meta_data”:[],”sku”:”76455″,”price”:1,”cog_item_cost”:0,”cog_item_total_cost”:0,”meta”:[]}],”tax_lines”:[{“id”:8029,”rate_code”:”CA-QC-TPS-1″,”rate_id”:13,”label”:”TPS”,”compound”:false,”tax_total”:”0.05″,”shipping_tax_total”:”0.00″,”meta_data”:[]},{“id”:8030,”rate_code”:”CA-QC-TVQ-2″,”rate_id”:14,”label”:”TVQ”,”compound”:false,”tax_total”:”0.10″,”shipping_tax_total”:”0.00″,”meta_data”:[]}],”shipping_lines”:[],”fee_lines”:[],”coupon_lines”:[],”refunds”:[],”cashier”:{“id”:”1″,”first_name”:”Michel”,”last_name”:”Petit”},”payment_details”:{“result”:”success”,”message”:”Montant soumit: $<\/span> 2.00<\/span>
Modifier: $<\/span> 0.85<\/span>”,”redirect”:””,”method_id”:”pos_cash”,”method_title”:”Esp\u00e8ce”,”paid”:true,”method_pos_cash”:{“tendered”:”2″,”change”:”0.8502″}},”total_discount”:”0.00″,”total_shipping”:”0.00″,”order_number”:”76461″,”updated_at”:”2019-02-15T10:30:46″,”billing_address”:{“first_name”:””,”last_name”:””,”company”:””,”address_1″:””,”address_2″:””,”city”:””,”state”:””,”postcode”:””,”country”:””,”email”:””,”phone”:””},”shipping_address”:{“first_name”:””,”last_name”:””,”company”:””,”address_1″:””,”address_2″:””,”city”:””,”state”:””,”postcode”:””,”country”:””},”completed_at”:”2019-02-15T10:30:45″,”_links”:{“self”:[{“href”:”https:\/\/souffledanscassette.com\/wp-json\/wc\/v3\/orders\/76461″}],”collection”:[{“href”:”https:\/\/souffledanscassette.com\/wp-json\/wc\/v3\/orders”}]}}

The page I need help with: [log in to see the link]