Error 502 upgrading from 8.1.2 to 8.3.2

when i visit the mattermost URL this return 502. the mattermost.log file report:

[2016/01/05 10:24:54 CET] [CRIT] The database schema version of 1.1.0 cannot be upgraded.  You must not skip a version.

i have update from 8.1.2 to 8.3.2

this is the forum post