A missing or incorrect license can block downloads – not just runtime execution.
In TIA Portal download dialog:
The "WinCC Viewer RT" download and installation issues are predominantly caused by source file corruption and environment incompatibilities rather than a software bug. By adhering to official Siemens channels for download and following the strict pre-requisite checklist (OS Version and .NET Framework), a successful installation can be guaranteed. wincc viewer rt download fix
Status: Issue Resolved. Procedure updated in internal knowledge base.
If you cannot disable the firewall permanently, configure these inbound rules on the Target PC: A missing or incorrect license can block downloads
| Port | Protocol | Service/Tool | |------|----------|---------------| | 102 | TCP | S7 Communication | | 135 | TCP | RPC Endpoint Mapper | | 1433 | TCP | SQL Server (WinCC DB) | | 50515–50520 | TCP | WinCC Download Service |
PowerShell script to add the rule (run as Admin): Viewer RT requires exactly that license – a
New-NetFirewallRule -DisplayName "WinCC RT Download" -Direction Inbound -Protocol TCP -LocalPort 50515-50520 -Action Allow
# Run as Administrator
del /q /s %TEMP%\SIEM_*
msiexec /unregister
msiexec /regserver
Attempting to download a WinCC V7.5 SP2 project to a WinCC Viewer RT V7.4 will fail. Siemens does not support backward compatibility for downloads.
Users experienced the following symptoms when attempting to deploy the WinCC Viewer RT: