I've been using Daemon::SchedulerCronTaskManager::Task###MailAccountFetch for the past few months and uncheck the fetchmail.
I have been recently encountering on the same error
"Error: Unable to register the process in the database. Is another instance still running?"
to fix it, i've been using this command
./otrs.Console.pl Maint::PostMaster::MailAccountFetch --force-pid
then after a few days it will run smoothly without any error but after a while or days the error will come back again.
I'm trying to see if there other application currently connected to our port.
but there's none. can you please help me how to completely fix it?
I'm just using the command above for a temporary fix.
Please help me how to fix it.