LibreOffice Calc will not link to external data via internet

OS Win 7 LibreOffice 3.5

Insert >Link to external data. Inserting a an internet URL results in

"The host name HTTP:// could not be resolved.

The Update. [Ed. note: “Then update” ?]

Tools >Options>Online Update can not be accessed via internet either.

I assume your firewall blocks LibreOffice’s attempts to connect to the internet. Please check your firewall settings and allow LibreOffice to make requests through the firewall.

See for instructions on how to configure the builtin firewall.

I excessively use External contents inserted to CALC via menu ‘Insert → Link to external data’ with LibreOffice German UI/Locale [Build-ID: 281b639-6baa1d3-ef66a77-d866f25-f36d45f] on German WIN7 Home Premium (64bit) and also did with versions before. We have “Bug 42377 - EDITING: Insert external data will not start with uncoded special characters in URL”, but symptoms there are different to the ones george mentions, so I also think it’s a firewall problem or similar.