Problems Loading Kexts on macOS 10.14.5 Beta 2
Tunnelblick may try to load a kext to control the VPN tunnel.
Note: If you are using a "tun" VPN, you can avoid needing to load a kext by doing the following:
The "dev-type tun" option causes OpenVPN to use a "tun" device, which requires a kext to be loaded. If a "dev-type tun" option is not present and a "dev tun" option is present, OpenVPN will use the "utun" device which is built into macOS and does not require a kext to be loaded.
If you are using a "tap" VPN, Tunnelblick must load a kext for your VPN to operate.
If you see the following on macOS 10.14.5 Beta 2 when using Tunnelblick 3.7.9beta05:
Tunnelblick was not able to load a device driver (kext) that is needed to connect...
You may have encountered a new macOS restriction on loading kexts which affects only Tunnelblick 3.7.9beta05 on that particular beta version of macOS. All other versions of Tunnelblick should work fine on that beta version of macOS, including other beta versions of Tunnelblick.
So either update to macOS 10.14.5 Beta 3 or update to a later version of Tunnelblick when one is available. (Until a later version is available, downgrade to Tunnelblick 3.7.8 or 3.7.9beta04.)
If that does not help, it is a different problem. Please see Errors Loading Kexts (Device Drivers) on macOS High Sierra (10.13) and higher and Errors Loading Kexts (Device Drivers).