Update local installation - from v23.0.02 to latest (Ver 26.)

I am trying to update a local installation from ver23 to ver26. I am using Xampp to load gibbon. When I copy the files to my gibbon folder I get an error
I have attached a picture of this error

I have backed up both the Gibbon folder and the Database.

Hi @rfrancois I’ve seen this error before when making multiple leaps forward in versions, which was caused by merging the new vendor folder into the old vendor. My recommendation would be to delete the /vendor folder from your Gibbon installation, then use a fresh copy of the /vendor from the InstallBundle for v26.

Thank You this solved my problem