If you are like me and only upgrade Identity server 4 after the current version has been stable for a while then its probably time to upgrade to the new version 2.4. For the most part you should just upgraded the dlls in your project. After that you can run it, however if you are using entity framework you may find the following error.
This is because a new table DeviceCodes was added. You will need to add this to your database.
You will need to add the following migration steps. The following are all of the DbContext that i have in my project currently. I run them all to check for any changes now that I have added all of the new dlls.
dotnet ef migrations add IDSUpgrade2.4 --context ConfigurationDbContext dotnet ef migrations add IDSUpgrade2.4 --context PersistedGrantDbContext dotnet ef migrations add IDSUpgrade2.4 --context ApplicationDbContext
Its up to you how often you update your project. As I have stated I like to wait at least a month before I update things not that I have ever seen the team have to roll back any major issues the Team working on the Identity server 4 project is very professional and appear to test their project fully before release. Updating your project is quite easy and should be painless.