Hello 
When trying to install an app, install fails because of an issue with doveadm. Trying the command alone raise the same result:
doveadm -f flow quota get -u MyUser
doveadm(root): Fatal: Unknown command ‘quota’, but plugin quota exists. Try to set mail_plugins=quota
I tried to remove and re-install dovecot, no change.
Do you know how I can fix this issue ? Thanks 
ljf
#2
Which YunoHost version is used ?
For the moment I think you can work around by stopping dovecot
ljf
#3
Note: if dovecot is stopped, you won’t be able to download your email.
Bram
#4
Which application have you tried to install? We need this information to be able to reproduce this bug.
Thanks for the report 
I used 2.4, now updated to 2.5, no change.
Ok, I’ll test that 
Bram
#6
Oh, and on which system? Are you using armbian?
ljf
#7
Are you on an arm board (rpi, olinuxino, internet cubre/Brique Internet, cubibox …) ?
Raspberry Pi 3
I tried with owncloud.
ljf
#9
What is the result of this command
sudo doveadm -f flow quota get -u USER
Replace USER by a yunohost user of your server
frju365
#11
Which app did you want to install ?
ljf
#12
I think your quota plugin is not setup due to an arm specificity (may be because recommends package are not set up)
Try to run grep mail_plugins /etc/dovecot/dovecot.conf
. You should get this:
root@yunohost:/home/vagrant# grep mail_plugins /etc/dovecot/dovecot.conf
mail_plugins = $mail_plugins quota
mail_plugins = $mail_plugins imap_quota antispam
mail_plugins = quota sieve
frju365
#14
can you install “dovecot-sieve” ?
[sudo apt install dovecot-sieve]
Then, give the result of "grep mail_plugins /etc/dovecot/dovecot.conf ".
ljf
#15
strange !
May be you or an app change the dovecot conf ?
If you want watch differences:
yunohost service regen-conf --with-diff dovecot
If you want restore the dovecot conf:
yunohost service regen-conf --force dovecot
Already done before those tests.
I just did it, no errors now. Let’s try again installing owncloud 
It works 
Thanks for your help ! 
(now let’s tackle let’s encrypt removing issues… ^^)