DBI connect(':localhost:3306','rvadmin_public',...) failed: Can't..

Problem

The following long error on RVskin Theme Manager or RVskin theme in control panel.

DBI connect(':localhost:3306','rvadmin_public',...) failed: Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2) at /usr/local/cpanel/Cpanel/RvMysql2.pm line 243
Carp::carp('DBI connect(\':localhost:3306\',\'rvadmin_public\',...) failed: ...') called at /usr/local/cpanel/perl/DBI.pm line 653
DBI::__ANON__(undef, undef) called at /usr/local/cpanel/perl/DBI.pm line 707
DBI::connect('DBI', 'DBI:mysql::localhost:3306', 'rvadmin_public', '4u,!BI8eX5r&') called at /usr/local/cpanel/Cpanel/RvMysql2.pm line 243
Cpanel::RvMysql2::RvMysql2_testremote('timeout', 5, 'passwd',……………………………………………………………
……..main::_api1('include', 'include', '/usr/local/cpanel/base/frontend/rvskin/rvbranding/indexheader.ht...', 'include', 'ARRAY(0x7f7cbf7539c0)', 'safe_html_encode', undef, undef) called at cpanel line 1572
main::real_exectag('<cpanel Rvskin="loadvars()">') called at cpanel line 4158
main::dotag_finished_headers(0) called at cpanel line 3978
main::cpanel_parseblock('<cpanel include="/usr/local/cpanel/base/frontend/rvskin/rvbrandi...') called at cpanel line 3892
main::y('GLOB(0x3ca38f0)') called at cpanel line 5257
main::run_standard_mode() called at cpanel line 785

Possible Cause
RVskin cannot find the file /tmp/mysql.sock. It might have lost from updating MySQL, etc.

Solution
You can fix the error by running the two following commands.

ln -s /var/lib/mysql/mysql.sock /tmp/mysql.sock
/scripts/restartsrv_mysql

If it returns an error File exists as following.

[root@{server} ~]# ln -s /var/lib/mysql/mysql.sock /tmp/mysql.sock

ln: failed to create symbolic link ‘/tmp/mysql.sock’: File exists

Try to create a new database for RVskin Manager usage, and insert it RVglobalsoft manager -> RVskin Theme Manager -> Configuration -> Database Setup .