9
Hi, Could u cehck your your list schema first though any rest client. It will show u the list structure which can help u to identify the colum name issue.
You can use " SharePoint REST Client " which is quit easy to use.
3
always post your code with question
it is difficult to understand your problem without code
1
Could you try to retrieve single column insted of all the columns . This will help in eliminating the column which is causing this issue.
1
Please check, if it is not related to permission. The user should have at least Read permission on list / list item to get the result.