SOLVED – Migrating from Siteground don't work

Think it was a plugin causing the problem… sorry
Hi, I have migrated a small site for testing the hosting on wpmu, the site had 2 issues when I started:
My original site is on MySQL v5.6.40-84.0-log whereas aworldofsmile.wpmudev.host is on MySQL v10.3.20-MariaDB-1:10.3.20+maria~bionic.
and
The original site uses apache whereas aworldofsmile.wpmudev.host uses nginx.
The site is installed with DIVI, and the builder is not working, I get the error:

ERROR: It had not been possible to open the file. Review your name and your permissions

.
And the pages look nothing like they should.
Is there some known issues regarding migrating from siteground, or Divi?