Updating from 3.6.1 to 3.7.0 got the following error.
However Motomo appears to have loaded OK afterwards. Will this error affect my analytics?
If you are able to run
./console core:update in the root folder of your installation.
Why if it seems to work fine? I don't think I have access to the server's console.
It shouldn't affect your analytics but may affect scheduled reports. You could try execute this MySQL query if you are familiar with databases:
ALTER TABLE piwik_report ADD column evolution_graph_within_period TINYINT(4) NOT NULL DEFAULT 0, ADD column evolution_graph_period_n INT(11) NULL;
Haven't tested the query but should work. You may need to replay piwik_report with a different value in case you use a different table prefix (if you don't know what it is, it likely doesn't need to be replaced)