Pictures uploading via the WYSIWYG Picture Manager fails

Q: When we use the picture upload dialogue, the popup asks for the path, when we press "go" in the dialogue nothing happens. We have tried to upload pictures to the "shared" folder manually and these are available in the pictures dialogue.

A: There are several possible causes if this issue:

1. This is most probably the issue with incorrect permissions. Please setup write permissions (755 or 777 on Linux/UNIX systems, depending on your web server configuration) to the "/admin/media_store" directory and its sub-directories and files recursively.
2. This may happen if "safe_mode" is enabled in PHP settings. To solve this issue, you need to disable safe_mode.
3. Another possible cause can be limited file size for pictures you're trying to upload. Use this guide to increase maximum allowed file size.