VCL Subscription Manager Fails to Connect via 4G


Due to ADSL issues, I am now connecting to the internet via a 4G connection, but this fails with the message:

[Window Title]
TMS Subscription Manager
[Main Instruction]
Cannot connect to the internet
Please check if a firewall or anti-virus software is not blocking internet access to TMS Subscription Manager or your proxy is configured correct.

All other software (Google, TeamViewer, Adobe, ...)  connect fine to the internet.

Very best regards,


Our software is not performing any kind of checks on the type of network.
It just tries to do HTTP GET requests to 
If this fails, there is a software issue (firewall / antivirus / proxy /...) or network issue.