Unable to locate libmysqlclient18 amd64 5.5.50-0ubuntu0.14.04.1 while installing

Hi there! I’m trying to install Kodi on my notebook running Lumbuntu. I’m stuck with this errors bellow after following the instalation guide.

The following NEW packages will be installed:
kodi kodi-bin libcec3 libcrossguid1 libgif5 liblockdev1 libmicrohttpd10
libmysqlclient18 libnfs1 libpcrecpp0 libplatform1 libsdl2-2.0-0
libshairplay0 libtinyxml2.6.2 python-bluez
0 upgraded, 15 newly installed, 0 to remove and 15 not upgraded.
Need to get 595 kB/26,4 MB of archives.
After this operation, 69,3 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
WARNING: The following packages cannot be authenticated!
liblockdev1 libmicrohttpd10 libtinyxml2.6.2 python-bluez
Install these packages without verification? [y/N] y
Err http://us.archive.ubuntu.com/ubuntu/ trusty-updates/main libmysqlclient18 amd64 5.5.50-0ubuntu0.14.04.1
404 Not Found [IP: 91.189.91.23 80]
Err http://security.ubuntu.com/ubuntu/ trusty-security/main libmysqlclient18 amd64 5.5.50-0ubuntu0.14.04.1
404 Not Found [IP: 91.189.91.26 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/m…_amd64.deb 404 Not Found [IP: 91.189.91.26 80]

Looking on Google I noticed that the file “libmysqlclient18 amd64 5.5.50-0ubuntu0.14.04.1” does not exist but the “libmysqlclient18 amd64 5.5.52-0ubuntu0.14.04.1” (note 5.5.52) exists…. can anyone help me on it?

Best regards
Capa