Hi the custom read fail is not a sap error its usually a qlikview error, when the records that you are trying to extract exceed the max rows in your connection string.
CUSTOM CONNECT TO "Provider=QvSAPDSOConnector.dll;ASHOST=00.00.00.00;SYSNR=10;CLIENT=800;ODSMaxRows=10000000;XUserId=SGDIdYZODLdGXSJObF;XPassword=ULeXUYRNJbaMXUVMXDJA;";
change the ODSMaxRows to a bigger value.
Just to test this theory set the ODSMaxRows=10000 and debug with a limited load of 5000 so not to exceed your 10,000 limit and if this is successful then the ODSMaxRow limit is your issue
Now if you get a different error such as 'File Exdata.cpp' this is related to SAP and there is not enough buffer in sap to complete your request, so either try and break your query in smaller chunk based on some field or get SAP to increase the available buffer for you