[Errors] Kubuntu won't boot

[ATATAT]

Hi everyone,
I recently happened to use my Kubuntu system and then reboot the computer. When it rebooted, GRUB worked fine, but Kubuntu wouldn't start anymore. Here you will find a photograph of the screen output I get if I try the safe mode (normally I would only get a black screen): https://imgur.com/a/z02Mn0o
The disk is encrypted, but I do know the password.
A list of things that I did before rebooting:
I've set the time from UTC to local time (since I'm dual-booting with Windows)
I've installed VirtualBox
I've also changed the time in the UEFI.
Necessary Information:

• What release of Kubuntu you are using.

I can't obtain version numbers, since the computer won't boot.

• If Kubuntu is installed, is it installed 'inside' of Windows (Wubi installation).

It's not a Wubi installation.

• What version of KDE you are using.

I can't obtain version numbers, since the computer won't boot.

• What version of Grub you are using.

I can't obtain version numbers, since the computer won't boot.

• What other Operating Systems are installed.

Windows 10, but on another disk.

Information about your PC:

• Type (Desktop or laptop)

Desktop.

• CPU (Central Processor Unit) make (Intel, AMD, ?) and whether 32-bit, 64-bit, or ?

AMD A6 5400K, 64 bit

• GPU (Graphics Processor Unit) manufacturer and model

AMD A6 5400K (it's an APU)

• RAM (how much installed)

4 GB

• HDs (number of and type internal - number of and type external)

2 internal

• Optical Drives (number of and type internal - number of and type external)

None

[claydoh]

Which version of Kubuntu did you install?
The image shows info relating to kernel 4.4.0 and Ubuntu 14.04, which is extremely old and reached end-of-life for the Kubuntu parts in 2017, and the rest of the OS in 2019.

What yoyur specific problem is, I cannot tell for sure, but it is possible either your encrypted drive is unable to be decrypted for some reason, or the drive may have issues. Or partitions changed?

[ATATAT]

Thanks for your answer.
It's an old version indeed, it could well be 14.04. I installed it maybe 1 or 2 years ago and I didn't update it because I almost never used it. I chose it because it was an LTS release, and I prefer those.
Now my question is: is it possible to diagnose or just fix my problem? (I believe it should be possible, also I haven't played with partitions or GRUB in any way).

[Snowhog]

Your best bet is to download the latest version of Kubuntu and do a fresh installation. If as you said "I installed it maybe 1 or 2 years ago and I didn't update it because I almost never used it.", it's likely that there isn't anything important on it anyway; you didn't state there was. Trying to troubleshoot issues on an EOL (End of Life) version of Kubuntu isn't something we here at KFN are prepared for or willing to assist in. EOL means 'no more support'. I don't mean to sound harsh, but that is just how it is.