Hello jean-pascal perrein !

Well, this is a not good way: I copy over all files from an original 10.0.3 zip => Same errors . For now, it's better for you to do the following:

1) clear manually the folders like cache, cache_public and tmp. And repeat the upgrade.

2) if it will not help then backup the files and folders of your current UNA, then install the clean 11.0.3 in the sub-folder, install your modules there (better in the same order as in the sys_modules table) then try to repeat the upgrade there. Inform us about the result.