Cronline added didn't remain on creating backup task in freepbx17

[ozarktech (Doug Kuhns)]

I"m setting up a backup to an ftp server on a new install of freepbx17 vm on hyperv. Everythings fine till I click submit, then I get this error.
Exception thrown with message “Cron line added didn’t remain in crontab on final check. Check /var/spool/asterisk/tmp/cron.error for reason.”

Viewing the cron.error file says bad day-of-week. I changed the day of week and changed to daily backup but still get the same error.

Stacktrace:
#8 Exception in /var/www/html/admin/libraries/BMO/Cron.class.php:130
#7 FreePBX\Cron:addLine in /var/www/html/admin/libraries/BMO/Cron.class.php:207
#6 FreePBX\Cron:add in /var/www/html/admin/modules/backup/Backup.class.php:1309
#5 FreePBX\modules\Backup:scheduleJobs in /var/www/html/admin/modules/backup/Backup.class.php:1466
#4 FreePBX\modules\Backup:updateBackupSetting in /var/www/html/admin/modules/backup/Backup.class.php:1340
#3 FreePBX\modules\Backup:updateBackup in /var/www/html/admin/modules/backup/Backup.class.php:216
#2 FreePBX\modules\Backup:doConfigPageInit in /var/www/html/admin/libraries/BMO/GuiHooks.class.php:292
#1 FreePBX\GuiHooks:doBMOConfigPage in /var/www/html/admin/libraries/BMO/GuiHooks.class.php:253
#0 FreePBX\GuiHooks:doConfigPageInits in /var/www/html/admin/config.php:449

crontab -u asterisk -e results:

[ozarktech (Doug Kuhns)]

I found help on another forum.

"I have seen it were it would do just like you are seeing, I think the way I fixed it was to switch to week, select a day of the week, then go back to month.

I am not 100% sure, but I think that is what it was when it happend to me. I just created a new task and it starts with Day of the week and has a day selected. When I fall back to Month, it leaves the day of the week selected, but then grays the whole box out.
See if that will get you going.
You may need to select all the days.
Or all the months."