Split Connector Error: "Can't write content text here".

I am creating an XML message using a Script connector:

<arc:set attr="output.filename" value="xmltriggerfile_[guid()].xml" />
<arc:set attr="output.filepath" value="[filepath]" />
<arc:set attr="output.data"><?xml version="1.0" encoding="UTF-8"?>
  <Schedule>
   <startDateTime>[_|now()|dateadd('day',-1, 'yyyy-MM-dd 00:00:00')]</startDateTime>
   <endDateTime>[_|now()|dateadd('day',-1, 'yyyy-MM-dd 23:59:59')]</endDateTime>
  <Results></Results>
</Schedule>      
</arc:set>

<arc:push item="output" />

This is then fed into a MySQL Lookup Connector which results in the following message

<Schedule>
  <startDateTime>2024-03-11 00:00:00</startDateTime>
  <endDateTime>2024-03-11 23:59:59</endDateTime>
  <Results>
    <TrackingEvent>
      <e_updated_at>2024-03-11T00:03:25.0000+00:00</e_updated_at>
      <e_shipment_id>20167856</e_shipment_id>
      <s_uuid>1eedb845-66bd-6fc2-8198-825a21bcab7e</s_uuid>
      <e_harmonised_status_id>134</e_harmonised_status_id>
      <e_created_at>2024-03-11T00:03:25.0000+00:00</e_created_at>
      <e_id>89298203</e_id>
      <e_carrier_message
      >Item received at inbound office of exchange</e_carrier_message>
      <e_source_id>1</e_source_id>
      <c_carrier_name>Jersey Post</c_carrier_name>
      <e_happened_at>2024-03-10T19:48:00.0000+00:00</e_happened_at>
      <e_parcel_id>20172761</e_parcel_id>
      <e_country_code>US</e_country_code>
      <e_sub_status>024</e_sub_status>
      <e_status>120</e_status>
      <e_location
      >United States Postal Service facility, ISC NEW YORK NY (USPS), US</e_location>
      <e_happened_at_timezone>UTC</e_happened_at_timezone>
      <e_source_type>Modules\Carriers\Carrier</e_source_type>
      <e_unique_sub_status>024</e_unique_sub_status>
      <p_id>20172761</p_id>
      <p_uuid>1eedb845-66c2-6d9c-a6b9-825a21bcab7e</p_uuid>
      <p_barcode>UM296646964JE</p_barcode>
      <p_tracking_number>UM296646964JE</p_tracking_number>
      <h_created_at>2022-10-10T10:40:51.0000+01:00</h_created_at>
      <h_id>134</h_id>
      <h_code>120-024</h_code>
      <h_updated_at>2022-10-10T10:40:51.0000+01:00</h_updated_at>
      <h_name>Internal movement within carrier network</h_name>
      <h_message>Item received at inbound office of exchange</h_message>
      <h_tenant_id>1</h_tenant_id>
      <h_stage>3</h_stage>
      <a_uuid>91730c91-f330-43b5-afb7-98034ee0bf1d</a_uuid>
    </TrackingEvent>
    <TrackingEvent>
      ...
    </TrackingEvent>
    ...
  </Results>
</Schedule>

But my Split Connector throws an error: “[xmltriggerfile_22297792350344c8a4a633c3eb4b297f.xml] Can't write content text here.”

Here’s my path

So not sure what this error means.

I’ve tried deleting the Split connector and creating it again. I’ve tried in a completely different workflow on our separate Test Instance of Arc. Same issue.

Could it be the way the original message has been created using a Script connector?