Is there anything more you can say about this? Did you try and chmod any of the files mentioned? Did you need to chmod for v10?

This is localhost Bitnami Wampstack. Never had to chmod anything for v10 (local or live) but I have tried with v11 to no avail so not sure what's causing this. v10 installs without issue is all I know for sure.

v11 explicitly scans permissions in a detailed way, while v10 just checks to see if PHP thinks files are writable.
My guess is that the server is not suEXEC, but has the web server user and the hosting account user in the same group, with default permissions to make things writable for that group.
If you can run who.php on your server and tell me the output that will help me confirm.

nt authority\system

Oh, it's a Windows server?

Oh of course, you said Wamp

I've looked at this, and I got a lot of errors on Windows IIS too. Windows permissions are much more complex than Linux ones, due to how access-control-lists and (on IIS) application pools work. I've made some improvements so it works better. But I've also simply disabled the permission check on the installer on Windows unless explicitly enabled via a URL flag because I'm concerned about performance.

Actually I'll add permissions check back in for Windows, but I'll make the basic permission check (which the installer does) work more like how it used to - checking writability directly rather than reading and comparing the individual permissions (slow). We'll then keep the more advanced check for the upgrader and the Health Check.

Excellent, thank you.

Had another attempt with latest files, failed on Step 5 again. Still got a big list of permission issues on initial install page but I notice there is a change from forward slashes to backslashes in the paths which is likely the cause:-

"Set additional permissions for W:\Bitnami\wampstack-8.0.20-0\apache2\htdocs\v11/uploads/website_specific/graph_test (execute)."

Also of note:- A Composr file, sources/hooks/systems/addon_registry/all_icons.php is missing – it needs to be uploaded.

13 corrupt files mentioned (I know this is due to alpha state):-

themes/default/templates/ECOM_TRANSACTION_BUTTON_VIA_CCBILL.tpl
themes/default/templates/ECOM_SUBSCRIPTION_BUTTON_VIA_CCBILL.tpl
themes/default/templates/HTML_HEAD.tpl
themes/default/templates/MEDIA_VIMEO.tpl
themes/default/css/news.css
themes/default/css/global.css
themes/default/javascript/webfontloader.js
themes/default/javascript/core_rich_media.js
lang/EN/galleries.ini
lang/EN/ecommerce.ini
lang/EN/cleanup.ini
lang/EN/cns_components.ini
data/db_meta.bin

Path issues (mixed slashes)