Manually update gone wrong, now trying to update through adminstrator

[YoDavish]

Hello Joomla support community,

I'm trying to resolve an issue with a recent upgrade from 3.5.0 to 3.8.0 on a test instance that didn't go well and was eventually manually forced to update. Afterwards, I ran the database fix to update the schemas but since then, I only have access to the administrator but not the frontend of the website and can't update any my plugins or extensions. I figured I would try to reinstall the core files again from 3.8.0, however, I am unable to with folder/file permission errors which were original set to 755 folders and 644 files. I had to change the file permission to 644 to get it to work. Now I'm stuck on this error when I try to reinstall the core files of 3.8.0:

"ERROR: could not open .../htdocs/components/com_contact/helpers/legacyrouter.php for writing"

Any ideas what to do next?

[YoDavish]

Never I got it to work. Had to change the permissions to each folder and file. After a long tedious process, I was able to update the core files again and able to see both the administrator and frontend page now. However, some of the custom made modules that were put into the article are not appearing on the test website. How can get I get these back in?

[Vlad17]

With IIS to make folders/files writable you need to assign IIS user (usually IUSR) to the site root folder on the folder's properties->securuty tab and give him "write" permissions propagating this change to subfolders. If it works you will see in admin panel - folders witable in green color. 755/644 is a UNIX thing.