Notifications not working any more

[Bert84]

I updated to 4.9700, and nothing works anymore. I took an old back up with V3.8153, and it works again. Only the notifications are not working anymore. The log file gives:

2018-07-21 16:17:30.584 Error: Prowl:
2018-07-21 16:17:30.585 Error: Notification sent (prowl) => Failed

2018-07-21 16:18:05.022 Error: SMTP Mailer: Error sending Email to: !
2018-07-21 16:18:05.023 Error: Failed to send Email notification!
2018-07-21 16:18:05.023 Error: Notification sent (email) => Failed
2018-07-21 16:18:05.076 Active notification Subsystems: email, prowl (2/12)

I have no idea what is wrong, does anyone has an idea?

Totally new installation with version 4.9796 works.

[Bert84]

New installation did the job