I have a channel (media) that has various custom fields, one a matrix field where you can post images to a gallery, I have already published 20 images to this gallery and everything worked as it should, now when I try to publish any more images it just won't work, no error message is given it just redirects to the CP homepage. Anyone ever came across this before??
Go to "Members" -> "Member Groups" -> "Edit Group" and check if option "Include Members in PUBLISH page multi-author list?" is set to "Yes".
Make sure you have privileges (if you are not a Super Admin) to edit that channel.
While editing channel entry go to "Options" and check if you are on the dropdown list "Authors".
If not - go to your profile settings -> Member Preferences and check option "Include user in PUBLISH page multi-author list?".
Go to entry you want to edit, change author to yourself and it should be working now.