Migration tool error

Hi,

I'm trying to migrate ISPConfig 3.1.2 on SuSE 42 to the newly installed 3.1.11 on Ubuntu 16.4 LTS with latest migration tool v2.
Its aborts with the error below.
1st client was successfully added (it visible on new install), 2nd failed. Nothing else seem to be imported.

I'm was sought that this could relate to mysql bug described here:
https://askubuntu.com/questions/428243/mysql-access-denied-for-user-rootlocalhost
And executed these commands:
UPDATE mysql.user
SET authentication_string=PASSWORD(''),
plugin='mysql_native_password'
WHERE User='root' AND Host='localhost';
However, it didn't helped.

Please advise what to do next.
Thanks in advance
*************************
2018-01-12 18:37:33 - [INFO] Migration tool version 2.0.1p2 started.
2018-01-12 18:38:07 - [INFO] Config file saved.
2018-01-12 18:38:07 - [INFO] Found 0 Reseller entries.
2018-01-12 18:38:07 - [INFO] Found 2 Client entries.
2018-01-12 18:38:07 - [INFO] Found 11 Domain entries.
2018-01-12 18:38:07 - [INFO] Found 3 WebDomain entries.
2018-01-12 18:38:07 - [INFO] Found 0 VHost SubDomain entries.
2018-01-12 18:38:07 - [INFO] Found 0 VHost AliasDomain entries.
2018-01-12 18:38:07 - [INFO] Found 0 AliasDomain entries.
2018-01-12 18:38:07 - [INFO] Found 0 SubDomain entries.
2018-01-12 18:38:07 - [INFO] Found 6 MailDomain entries.
2018-01-12 18:38:07 - [INFO] Found 0 MailAliasDomain entries.
2018-01-12 18:38:07 - [INFO] Found 51 MailUser entries.
2018-01-12 18:38:07 - [INFO] Found 1 MailForward entries.
2018-01-12 18:38:07 - [INFO] Found 14 MailAlias entries.
2018-01-12 18:38:07 - [INFO] Found 0 MailCatchAll entries.
2018-01-12 18:38:07 - [INFO] Found 0 MailFilter entries.
2018-01-12 18:38:07 - [INFO] Found 0 MailTransport entries.
2018-01-12 18:38:07 - [INFO] Found 0 MailRelayRecipient entries.
2018-01-12 18:38:07 - [INFO] Found 62 SpamFilter entries.
2018-01-12 18:38:07 - [INFO] Found 2 SpamFilter Whitelist entries.
2018-01-12 18:38:07 - [INFO] Found 0 SpamFilter Blacklist entries.
2018-01-12 18:38:07 - [INFO] Found 0 Mailing List entries.
2018-01-12 18:38:07 - [INFO] Found 2 FTP User entries.
2018-01-12 18:38:07 - [INFO] Found 0 Cron Jobs entries.
2018-01-12 18:38:07 - [INFO] Found 4 Database User entries.
2018-01-12 18:38:07 - [INFO] Found 4 Database entries.
2018-01-12 18:38:07 - [INFO] Found 0 Protected Folder entries.
2018-01-12 18:38:07 - [INFO] Found 0 Protected Folder User entries.
2018-01-12 18:38:07 - [INFO] Found 10 DNS Zone entries.
2018-01-12 18:38:07 - [INFO] Found 79 DNS Record entries.
2018-01-12 18:38:07 - [INFO] Found 0 Shell User entries.
2018-01-12 18:38:07 - [INFO] Found 0 DataCopy entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice company entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice settings entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice vat rate entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice sepa mandate entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice message template entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice payment term entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice client settings entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice item template entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice item template custom field entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice item category entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice recurring item entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice item entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice message entries.
2018-01-12 18:38:07 - [INFO] Found 0 invoice sepa xml export entries.
2018-01-12 18:38:18 - [INFO] Successfully executed command mysql -h localhost -u 'root' -p'mypassword****' -e "SELECT VERSION();"
2018-01-12 18:38:18 - [INFO] Config file saved.
2018-01-12 18:38:18 - [ERROR] Invalid json data received for client_add: <div class='alert alert-danger clear'>
<div class='alert-label'><strong><tmpl_var name="error_txt"></strong></div>
<div class='alert-content'>
<ol>
<li>Possible attack detected. This action has been logged.</li>
</ol>
</div>
</div>
2018-01-12 18:38:19 - [ERROR] Invalid json data received for client_add: <div class='alert alert-danger clear'>
<div class='alert-label'><strong><tmpl_var name="error_txt"></strong></div>
<div class='alert-content'>
<ol>
<li>Possible attack detected. This action has been logged.</li>
</ol>
</div>
</div>
2018-01-12 18:38:19 - [ERROR] Invalid json data received for client_add: <div class='alert alert-danger clear'>
<div class='alert-label'><strong><tmpl_var name="error_txt"></strong></div>
<div class='alert-content'>
<ol>
<li>Possible attack detected. This action has been logged.</li>
</ol>
</div>
</div>
2018-01-12 18:38:19 - [ERROR] API call to client_add failed.