NCBI is switching to HTTPS-only access after September 30, 2016 to comply with federal requirements (https://https.cio.gov/).
Any software that depends on NCBI APIs or on the NCBI C++ or SRA toolkits may break after this date unless they are updated to access NCBI over HTTPS.
What should you do?
Make sure you're using the most recent versions of the C++ and SRA toolkits. Watch for releases later this month.
Contact your software vendor about their transition plans.
Update all API calls to use HTTPS.