This read access is a minimum requirement. If the file exists and the ULR is correct, then probably something is wrong with the access rights. How they are set depends on your web server. In the typical installation on Linux with the Apache web server, the access rights depend on the directory and file permissions. And of the .htaccess files, which can also be found in the subdirectories of DokuWiki. They determine what the web server is allowed to deliver and what not.
I found something very interesting. Someone with obviously the same problem as you, has found the following solution:
Just tried with Apache 2.2 instead of 2.4 and it works
Source:
https://forum.dokuwiki.org/post/62975
This fits in with my idea that your provider has changed the web server version.
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After I had written all these stuff, then I have probably found the solution here:
https://github.com/arsava/dokuwiki-template-vector/issues/63
As far as I understand, you have to change the .htaccess file in the root directory of the vector template:
https://github.com/arsava/dokuwiki-template-vector/blob/master/.htaccess
Feedback welcome, especially for the support of other users!
- Michael Sy.