Hello,
Is there a documentation to upgrade manually a website to 8.5.7 to 9 version?
Hi
I’ve already updated a few pages by simply replacing the Concrete folder and visit main url after change - just like in version 8. Overall no problem, sometimes something popped up (little error) but nothing important. So far, after the update, all pages work without problems 
Of course, there were changes in the theme (Bootstrap 3 to 5 change and other). It is important to back up your files and databases before updating.
Hi,
Thank you to share your experience!
Have you taken note of the errors and the solutions you have provided to correct them?
Unfortunately, I did not note exactly what these errors were. It happened once or twice. Then I ran the update again - I didn’t dig into it. From what I remember, there were also errors resulting from the fact that not all files were uploaded to the server - so not related to the update as such. What I was doing was mostly template work. It was a lot. Switching from Boostrap 3 to 5 to keep all blocks working properly. FontAwesome update, some custom scripts updated (to run on jquery 3.6.x), custom templates updated for page list block and other blocks where something changed in version 9. Overall in my experience, and I’ve already updated from 10 pages or more - it was all done smoothly and without major problems.