Hi there I have just installed and configured invoice manager following your instructions. I created a test customer and then proceeded to create a test invoice but after enter all the details and clicking save a new pages loads with just a page of code as follows

{"notifications":[{"message":"Invoice Saved!","type":"message"}],"content":{"id":"7","created_by":"442","user_id":1,"added":"2017-06-15 20:25:50","to_name":"","to_address":"58 address\r\nHereford","invoice_num":"2017-4","real_invoice_num":"4","from_name":"Design Echo","from_address":"58 address\r\nHereford\r\nHR1 1EZ","from_num":"de001","invoice_date":"2017-06-15 00:00:00","publish":1,"notes":"","template_id":"1","taxes":"","start_publish":"0000-00-00 00:00:00","end_publish":"0000-00-00 00:00:00","currency_before":"\u00a3","currency_after":"","status":"Pending","to_email":"anything@designecho.co.uk","to_company":"Test Company","from_phone":"07777777777","from_url":"www.designecho.co.uk","from_email":"anything@designecho.co.uk","discount":"0.0000","invoice_duedate":"0000-00-00 00:00:00","admin_notes":"","to_city":"hereford","to_state":"herefordshire","to_country":"united kingdon","to_vatid":"","to_zipcode":"hr1 1ez","rec_year":"0","rec_month":"0","rec_day":"0","rec_nextdate":"0000-00-00","is_recurrent":0,"to_phone":"01432 345678","external_type":"","external_id":"0","external_ref":"","type":"1","rec_email":"0","auth_code":"bNt4neMbl3QcF0pmEocXoxPsdi7iX8HZj3ZuNiG8ssqyA6RLQHXHmtabfyjWMyw1","computed_status":"pending","computed_total":"80.0000","computed_subtotal":"80.0000","computed":"{\"total\":80,\"subtotal\":80,\"subtotal_items\":80,\"total_paid\":{\"total_paid\":null,\"paid_payments\":\"0\"},\"total_unpaid\":{\"total_unpaid\":\"80.00\",\"unpaid_payments\":\"1\"},\"taxes\":[]}","language":"en-GB","last_sent":"0000-00-00 00:00:00","username":"No","contact_name":"Test Customer","joomla_user_id":"0","subtotal":80,"subtotal_items":80,"display_taxes":[],"total":80,"total_paid":null,"paid_payments":0,"total_unpaid":"80.00","unpaid_payments":1,"total_unpaid_ontime":"80.00","unpaid_payments_ontime":1,"unpaid_payments_notontime":0,"formatted_date":"15 Jun 2017","formatted_total":"\u00a380.00","formatted_subtotal":"\u00a380.00","formatted_total_paid":"\u00a30.00","payment_class":" notontime","rec_tooltip":"Next recurrency: 30 November -0001","allow_edit":1,"is_quote":0,"edit_link":"\/administrator\/index.php?option=com_invoices&controller=invoice&tmpl=component&task=edit&cid[]=7&layout=form&modal=1","link":"\/administrator\/index.php?option=com_invoices&controller=invoice&view=invoice&cid[]=7&tmpl=component","link_contact":"\/administrator\/index.php?option=com_invoices&controller=contact&task=edit&cid[]=1","link_payments":"\/administrator\/index.php?option=com_invoices&controller=payments&invoice_id=7","link_new_payment":"\/administrator\/index.php?option=com_invoices&controller=payment&task=edit&cid[]=0&invoice_id=7&from=invoices","pdf_link":"\/administrator\/index.php?option=com_invoices&view=invoice&format=dompdf&cid[]=7","email_link":"\/administrator\/index.php?option=com_invoices&controller=invoice&task=send_email&cid[]=7&ajax=1","status_class":"warning","last_sent_formatted":"Not sent","sent":0}}

please can you advise?? many thanks