I have the Caja read-only top-level directory problem and I confirm what others have seen for years with an external USB SD card reader but now in September 2016 on Ubuntu-Mate 16.04 including mate 1.12.1. I have attached my xsession errors in case there is a clue there. The last line had a g-io-error-quark. No problems with command line moves or copies.
** Attachment added: ".xession-errors" https://bugs.launchpad.net/linuxmint/+bug/1218076/+attachment/4744184/+files/.xsession-errors -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1218076 Title: nemo and caja says vfat/fat32 usb flash drive are read-only - not so... To manage notifications about this bug go to: https://bugs.launchpad.net/linuxmint/+bug/1218076/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs