Hard reboot corrupted/removed my Qt library. Couldn't run GUI apps

Why did you do a *hard reset*? Why not safely shutdown? via SysRq commands direct to kernel etc... as these allow you to sync file-systems, reboot/turn-off & more via direct command to the Linux kernel (ie. Linux specific and not specific to Ubuntu) bypassing any stuck UI/GUI etc... all it requires is a real keyboard (*meaning you can't use on-screen GUI keyboard like on an android phone etc*). You can also re-install Ubuntu Desktop systems without loss of data files, and having the *manually installed* packages (ie. those you added) also re-install automatically; so re-install is quick..

If you *force* reset without ***clean*** shutdown (inc. power outage etc); I'd not reboot into the system until I've performed file-system checks anyway... If any errors are detected they'll be fixed, and after that I'd expect normal reboot to my normal system without any problems... My current system is ~new, but my prior old [2009 dell] died late last year, but it had 10+ *release-upgrades* during its life before the PSU died & I finally replaced it; no re-install was required, which is what I'd expect from a Ubuntu system (& mine was a really bloated one too!)

@guiverc "Why did you do a hard reset?" I couldn't see the screen

@guiverc But either way, surely a hard-restart is sometimes required, like if a machine freezes etc?

If a *hard restart* is required you've a 50% chance of power or hardware failure occurred in my experience; ie. that's useful detail that tells you need to check your hardware (you still should use SysRq first as responses to commands gives detailed knowledge as to problem!). *hard restart* is required due to software on a kernel panic which is usually evident on the screen etc & thus kernel can't respond to SysRq commands where you'll need to hardware-restart there too but mostly this is result of a poor change made in the prior session which you should know about & be on lookout for

You don't need a GUI/UI to use sysrq; as it's commands direct to the kernel & bypass any UI/GUI/terminal etc; the hardware (*if you can see it, but SysRq commands need to be entered directly into machine via direct terminal*) will provide clues as to response in most cases (*though location; eg. noise changes of a single box in a rack of many in a room of many racks can still make it hard, but usually recognizable*) regardless it allows you to command kernel directly & gain knowledge from the responses as kernel speaks to hardware thus machine itself can provide the clues.. GUI/UI irrelevant

If I ever have this problem again, what is it I should do? Put the Ubuntu installation drive back in, run the installer but choose a different option? And what will this keep/destroy?

I sit in a Tesla and translated this thread with Ai: