Enabling multisite with custom table prefix not work

Hi,
I am trying to enable multisite but the tables is not created when I add in wp-config.php define(‘MULTISITE’, true), but an error appear:

Error establishing a database connection

In log I can see:

[12-Oct-2017 05:53:33 UTC] WordPress database error Unknown column ‘wp_’ in ‘field list’ for query SELECT wp_

Since I have custom table prefix in config, seem that installer of extra tables for multisite use default prefix wp_

Or I missed something?

I posted also here
https://core.trac.www.ads-software.com/ticket/42194

Reply was:

—
For support I suggest using our support forums at https://www.ads-software.com/support/. We also have a codex page for setting up a multisite install, note the WP_ALLOW_MULTISITE constant.
—

But when I use define(‘WP_ALLOW_MULTISITE’, true);
then nothing happen, it’s like ignored.
It’s loaded single site, and tables is not created.