Oliver,
you expect others to suggest “helpful” information. What you deem “helpful” is highly depending on your expectation level and your own level of skills and knowledge. The level of information you gave us in your first post was vague. You could have helped us helping you in following the guideline
Some answers, my own inculded, would have been different, had this information been given in your initial post.
However, your backup strategy obviously does not match your own expectation. Guess you will change that in the future.
I’m not an expert in booting Linux, although my PC uses Linux. But I know that the message
indicates an error with filesystem handling. To find the root cause an examination of the boot log messages is needed. And to fix it you need write access to the system, either by entering commands on the shell (you need monitor and keyboard attached to the RasPi for that) or by editing files on the SD card in another system. Which should not be a Windows system (don’t know whether there are even tools/drivers that can write to Linux file systems from Windows).
It is your decision if you want to follow the route down to accept suggestions from others and learn something or if you rather take the route to use your backup with adding your changes on top of that or even a newly built SD card.
This one I want to comment finally:
@Bruce_Osborne is one of the most active community members, helping a lot of others here since he became a member. Treating him like that might easily have the effect of others joining him in leaving you alone with your issues.