Connector error: Unexpected character encountered while parsing value: <. Path '', line 0, position 0.

[Koen_D]

Dear Qlik Experts,

I'm setting up an OAuth2 API connection in Qlik with Exact Online. I've managed to extract a refresh and access token, however when I try to access the end point with a GET call I get the following error:

(Connector error: Unexpected character encountered while parsing value: <. Path '', line 0, position 0.)

I've tried everything to fix it, but I can't seem to find a solution. I've used the following guides to get to this point:

https://community.qlik.com/t5/Qlik-Sense-Documents/Handling-Refresh-Tokens-with-the-Qlik-REST-Connec... 

https://community.qlik.com/t5/Connectivity-Data-Prep/QLIK-REST-Connector-and-OAuth2/td-p/1846711 

Code:

LIB CONNECT TO 'REST_GET';

MasterTable:
SQL SELECT
"Code"
FROM JSON (wrap on) "root" 
WITH CONNECTION (
URL "$(vURL)",
HTTPHEADER "Authorization" "Bearer $(vAccessToken)",
BODY "$(vRequestBody)"
);

[Koen_D]

To be more specific, I've tried to retrieve administration codes from Exact Online, using the following exact code:

LIB CONNECT TO 'REST_GET';

set vContentType = 'application/x-www-form-urlencoded';
set vURL = 'https://start.exactonline.nl/docs/XMLDivisions.aspx';
set vRequestBody = '';

MasterTable:
SQL SELECT
"Code"
FROM JSON (wrap on) "root"
WITH CONNECTION (
URL "$(vURL)",
HTTPHEADER "Authorization" "Bearer $(vAccessToken)",
BODY "$(vRequestBody)"
);