Well, all things must improve…
This site has been hosted on an aging openVZ VPS… Since openVZ does inherit the kernel from the host this is limited to an old version of Ubuntu. While the host limits this to Ubuntu 14.04 we have migrated it 16.04… however THAT is the limit of the old kernel…
THUS, finally I found the time to migrate this to a KVM based VPS… where I have also changed from the aging VESTACP to the more modern fork HESTIA…
This wordpress migrated WITHOUT ANY errors from the VESTACP Backup-File to the HESTIA restore (actually did the entire domain, dns, exim and MySQL in a single step… YEAH!
Only the WEBTREES application had a slight flaw… it does store the internal server path in the database… while consuming extra time … a simple edit in the database was all the was needed…
In summary, VESTACP/HESTIA allow for very easy server to server migration of entire domains!