Checked and troubleshoot the issue of FSRI regarding  POS2NAV. All the users trying to upload encountered an error "The underlying connection was closed: An unexpected error occurred on a receive". Checked the connectivity if the client pc can ping the servers. Then tried if they can access the NAV, also tried reconfiguring the POS2NAV. Everything is working. Seek assistance from Infra team to see if this is a connection error.