[SOLVED] Issue after upgrade of OJS from 3.0.2 to 3.1.0-1

Hello, After I completed upgrade from OJS from 3.0.2 to 3.1.0-1 I experience the following issues:
Masthead page in Settings/journal and
Settings/Website/information do not open at all. No spinner, just blank where it should be content of that page. The rest of interface is OK.
Here are the lines from php error log:
[Wed Jan 31 03:35:52.373979 2018] [:error] [pid 1308] [client] PHP Warning: array_merge(): Argument #2 is not an array in /var/sentora/hostdata/admin/public_html/thermal-science_tech/journal/lib/pkp/classes/core/PKPApplication.inc.php on line 578
[Wed Jan 31 03:35:52.374052 2018] [:error] [pid 1308] [client] PHP Warning: Invalid argument supplied for foreach() in /var/sentora/hostdata/admin/public_html/thermal-science_tech/journal/plugins/generic/recommendByAuthor/RecommendByAuthorPlugin.inc.php on line 114

Actually, hosting company asked me to move installation to new server. I upgraded it and moved to new server. but on new server server connection was default utf8mb4_general_ci. My database was utf8_general_ci.

When I changed server connection from utf8mb4_general_ci to utf8_general_ci everything was fine and I see all pages correctly. Strange but it works.