GET Notes returns INTERNAL_ERROR on API v2

GET Notes returns INTERNAL_ERROR on API v2

When I send a request to https://www.zohoapis.com/crm/v2/Notes, API returns me the next response:
{
"code": "INTERNAL_ERROR",
"details": [],
"message": "Internal Server Error",
"status": "error"
}
Please, let me know how to fix this problem.