I don't get it

[KvadratGnezdo]

For some weird reason my LDD has lost a LOT of parts and has basically downgraded its list back to 2007ish levels (PF are virtually non-existent, no rounded slopes etc). Is this a common thing or not? Im new to the LDD and is there any solution to this problem?

[SylvainLS]

And LDD can’t connect to the internet?

If the version is 4.3.11 but the brick version isn’t 2670, then you’ve installed the infamous 4.3.12, which is not a real update, it’s a botched attempt to fix installation problems of Windows 10.

See

 there’s a link to a correct copy of 4.3.11 installer and several explanations on how to install it on Windows 10 if you have troubles.

[JintaiZ]

Upgrading it again could work