PLESK Debian 7 several problems

[AlkatraZ]

PRODUCT, VERSION, MICROUPDATE, OPERATING SYSTEM, ARCHITECTURE
PLESK 11.5.30 Update #14, Debian 7.0 x64

PROBLEM DESCRIPTION
There are some nasty problems:

1) Tools & Settings -> License Management does not work (nginx: 502 Bad Gateway)

2) After the server restarts, all sites are unavailable. After visit to the Tools & Settings -> Services Management, turn off, and then again turn on Nginx, sites become visible.

3) Tools & Settings -> Backup Manager, Scheduled Backup to personal FTP repository does not work. All the settings are correct, but the backup is not created, a scheduled task is not created.

 

[AlkatraZ]

After Microupdate #15 have the same problem:
License Manager does not work (nginx: 502 Bad Gateway),
Scheduled Backup does not work,
After the server restarts, all sites are unavailable, until restart Nginx

 

[AlkatraZ]

11.5.30 Update #19
the problem is not solved yet
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If PLESK on DEBIAN 7 is insoluble problems, then tell me which of the platforms is currently working without problems?