How do I go backward from 9.0 to 8.6

[SacAutos]

The so-called upgrade from 8.6 to 9.0 has been a nightmare. In order to save my business, I need to go backward. I've got another server still running 8.6 . I've tried running the migration manager from the 8.6 box and I get this error message:

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

Is there a known manual method of backing-up and restoring a domain with it's web content, databases and emails from 9.0 back to 8.6?

 

[SacAutos]

I'll follow up on this myself. There appears to be no way that I can find to back-port your sites via automation from 9.0 back to 8.6 . I'm particularly irritated by this whole ordeal and will be remarking on it in a separate top-level post.