after install 7.3 - timeline error

see screen shot

how do I fix ?

The actual error message is not visible in your screenshot.
If you copy and paste the error, it may give more useful information.

-- -- There are errors in the following MySQL queries:
-- -- Error: 

CREATE TABLE `bx_wall_voting` (`wall_id` bigint(8) NOT NULL default '0',`wall_rating_count` int(11) NOT NULL default '0',`wall_rating_sum` int(11) NOT NULL default '0',UNIQUE KEY `wall_id` (`wall_id`)) ENGINE=MyISAM DEFAULT CHARSET=utf8;

-- -- Error: 

CREATE TABLE `bx_wall_voting_track` (`wall_id` bigint(8) NOT NULL default '0',`wall_ip` varchar(20) default NULL,`wall_date` datetime default NULL,KEY `wall_ip` (`wall_ip`,`wall_id`)) ENGINE=MyISAM DEFAULT CHARSET=utf8;

Unfortunately there is nothing in those lines that give a clue to what the problem is. If you run that SQL on the appropriate DB in PHPMyadmin, you will hopefully get a useful error message.

#1050 - Table 'bx_wall_voting' already exists  

should I delete this table then try to install timeline ? if so how do I delete it ?

thank you

I fixed it 

thank you for the help

Thank you for the report, there is a problem with module uninstall:

https://github.com/boonex/dolphin.pro/issues/282