Vb.Net help - error DSC-0018

[Nick257]

Hi guys,

I'm, Using vb.net 2015, following guide from James Butlers excellent book on "Programming for Betfair".

The error (mandatory parameter missing!?!):
[{"jsonrpc":"2.0","error":{"code":-32602,"message":"DSC-0018"},"id":1}]

The request:

[
{
"jsonrpc":"2.0",
"method":"SportsAPING/v1.0/listMarketCatalogue",
"params":{
"filter":{
"eventTypeIds":[
"7"
],
"marketCountries":["GB"],
"marketTypeCodes":["WIN"],
"marketStartTime":{
"from":"2017-10-05T09:45:20Z",
"to":"2017-10-05T23:00:00Z"
}
},
"sort":"FIRST_TO_START",
"maxresults":"200",
"marketProjection":[
"MARKET_START_TIME",
"RUNNER_DESCRIPTION",
"EVENT"
]
},
"id":1
}
]


Presently not sure if its my JSON request, or perhaps the header... I've triple checked data types, all seem to be ok...

I've tried 2 variations of header:
1. With the vb "webRequest" object, explicitly providing "X-Application:" & my Appkey, the ""X-Authentication:" with current session token, and ContentType "application/json"
2. Several forum articles seem to suggest the header option "Accept:application/json" is required... which is not available in the vb "WebRequest" object, so have also tried vb "HttpWebRequest" (which allows "accept" to be specified as a header option).

Have even tried a Wireshark trace... but of course comms are encrypted, so not much to see!

Bit stumped! thanks for looking...

[jptrader]

Try maxResults instead of maxresults

[Nick257]

yeah... that was it ! jeeze louis. thanks!

[markymark777]

Try maxResults instead of maxresults

Thank you!!!!