Should the thumbnails and preview images be created yet the spinning icon is being shown, the issue is most certainly a permissions problem: the web server cannot access the images in the subfolders thumbs
inside the cache folder. You can test whether this truly is the case by entering the URL to the preview image directly into your browser. If you get a message like Access forbidden
, the web server user account cannot fetch the image. Usually, deleting the folders thumbs
and manually re-creating them using your own FTP account helps because it makes sure your personal (FTP) user account becomes the owner of these folders. Once the empty folders are manually created, files created within by sigplus are usually accessible to the web server.
If thumbnails and preview images are not created at all then the user account running Joomla (and hence sigplus) has no permissions to write in those folders (or create the folders as a starter). This happens when Joomla runs under a restricted account rather than personifying your own user account. Even if not a good idea in general, manually re-creating and elevating the permissions on there two folders to 777 should solve the problem because it lets everyone (including the restricted account) to write files in them.
If the installer fails for an extension, there is a high chance that the statement permissions are all OK
is terribly wrong. See the sigplus FAQ for a list of what is copied to where:
Upon installation, the Joomla installer copies files in the plg_sigplus.tgz package to the following file system locations:
- en-GB.plg_content_sigplus.ini is copied to administrator/language/en-GB/en-GB.plg_content_sigplus.ini
- xx-XX.plg_content_sigplus.ini is copied to administrator/language/xx-XX/xx-XX.plg_content_sigplus.ini where xx-XX is the language identifier
- sigplus.php is copied to plugins/content/sigplus.php
- sigplus.xml is copied to plugins/content/sigplus.xml
- the entire contents of the folder sigplus in plg_sigplus.tgz is copied to plugins/content/sigplus
If any of there files cannot be written to, your get the installer fails message. (If you had sigplus previously installed, you might simply overwrite the existing files. Of course, you really should get your system's permissions in shape but as a work-around, manually copying the files helps.)