Plesk Fatal Error during migration

[kuhle]

Hi,

I am trying to migrate from 8.1 to 8.6. If I try to migrate a single domain or client, it appears to be OK. However, I have tried to do the whole server, and I am getting:

ERROR: PleskFatalException
Up LevelUp Level
Unable execute MigrationWait::make(): Unable to create bar: assigned values not like "minimal value <= current value <= maximal value (!= 0)

0: /usr/local/psa/admin/plib/common_func.php3:190
psaerror(string 'Unable execute MigrationWait::make(): Unable to create bar: assigned values not like "minimal value <= current value <= maximal value (!= 0)')
1: /usr/local/psa/admin/plib/PMM/MigrationWait.php:282
MigrationWait->make()
2: /usr/local/psa/admin/htdocs/server/PMM/main.php:25

Can anyone help me on this?