snap cannot find symbolic-linked directories; module s"gail" & "atk-bridge" fail to load

[sadhu44]

Linux Mint 20.2 Uma, 64-bit, Cinnamon, with Python3 installed. I completely removed all traces of snap (including the /snap directory) and snapd, then re-installed snap.d and pinta, and attempted to run it from the command line.

sadhu@desk:~$ sudo snap install pinta
2021-12-16T08:34:11+05:30 INFO Waiting for automatic snapd restart...
pinta 1.7.1 from James Carroll installed
sadhu@desk:~$ pinta
update.go:85: cannot change mount namespace according to change mount (/snap/gtk-common-themes/1519/share/gtk2/Materia-compact /snap/pinta/15/data-dir/themes/Materia-compact none bind,ro 0 0): cannot write to "/snap/gtk-common-themes/1519/share/gtk2/Materia-compact" because it would affect the host in "/snap"
update.go:85: cannot change mount namespace according to change mount (/snap/gtk-common-themes/1519/share/gtk2/Materia-dark-compact /snap/pinta/15/data-dir/themes/Materia-dark-compact none bind,ro 0 0): cannot write to "/snap/gtk-common-themes/1519/share/gtk2/Materia-dark-compact" because it would affect the host in "/snap"
realpath: /home/sadhu/Documents: No such file or directory
realpath: /home/sadhu/Desktop: No such file or directory
realpath: /home/sadhu/Downloads: No such file or directory
realpath: /home/sadhu/Music: No such file or directory
realpath: /home/sadhu/Pictures: No such file or directory
realpath: /home/sadhu/Videos: No such file or directory
Gtk-Message: 08:46:35.520: Failed to load module "gail"
Gtk-Message: 08:46:35.520: Failed to load module "atk-bridge"
sadhu@desk:~$

I had a similar problem with ksnip: snap can't find my /ddr directory (which contains Documents), nor my /zmv directory which contas Pictures, Videos, Music, and Downloads.

I can't load a file in pinta ('/home/sadhu/Documents' doesn't appear on the file tree in pinta -- and ksnip when it was loaded before)

[sadhu44 (sadhu44)]

The above directories /ddr and /zmv are the mount points for the partitions that contain my data. The are backed up nightly to an external HDD. ~/Documents --> /ddr/Documents. Ditto for Downloads, etc. /snap is in the root partition along with /opt, /usr, /etc, etc. Thus my data is available to mint19.3 (in another partition) and xubuntu (in still another partition).