Error MySql after unsuccessful update

mysql-server-5.5 (5.5.54-0+deb8u1) wird eingerichtet ...
insserv: warning: script 'maldet.save.1' missing LSB tags and overrides
insserv: script mysql41: service mysql already provided!
mysql-server (5.5.54-0+deb8u1) wird eingerichtet ...
[FATAL] iMSCP::Bootstrapper::_dbConnect: Could not connect to the SQL server: DBI connect('database=imscp;host=localhost;port=3306','imscp_user',...) failed: Access denied for user 'imscp_user'@'localhost' (using password: YES) at /var/www/imscp/engine/PerlLib/iMSCP/Database/mysql.pm line 98.
Fortschritt: [ 55%] [####################################################################################...................................................................]
E: Problem executing scripts DPkg::Post-Invoke 'if [ -x /usr/local/sbin/imscp-dpkg-post-invoke.pl -a ${IMSCP_SETUP:=0} -eq 0 ]; then /usr/bin/perl /usr/local/sbin/imscp-dpkg-post-invoke.pl -d; fi'
E: Sub-process returned an error code

root@www:/usr/local/src/imscp-1.3.16# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 105
Server version: 5.5.54-0+deb8u1 (Debian)

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