UPGRADING OJS 3.0.0 A database error has occurred: Duplicate entry 'tinymceplugin-0-enabled' for key 'plugin_settings_pkey'

Dear OJS Team,

Thanks for all your attemps for development of OJS.
There is a serious problem in upgrading from OJS 2.X to 3.

There is an error at middle of upgrading: "
A database error has occurred: Table ‘issue_galleys_stats_migration’ already exists"

Even when the issue_galleys_stats_migration is deleted. again there will be an error of 'A database error has occurred: Duplicate entry ‘defaultthemeplugin-0-enabled’ for key ‘plugin_settings_pkey’

(The images of the both the error have been attached along this email)

There are may users that want to upgrade from 2.x to 3, but they are not able to do that. If you search in forums of OJS, you can see nobody still was able to solve this problem.

On the other hand OJS 2.x has some security bugs and hackers easily hack the OJS 2.x while we cannot do anything to protect our websites.

We appreciate if you guide us how to solve the problem that we face for upgrading from OJS 2.x to 3.

Thanks for your time for reading our email.

Regards
Editorial Team