Warning: Cannot use a scalar value as an array

Getting in the following warnings once activated.

Warning: Cannot use a scalar value as an array in /home/printstore/public_html/wp-content/plugins/woocommerce-mailchimp/includes/class-ss-wc-mailchimp-plugin.php on line 444

-- WordPress Configuration

Version:                  4.7.3
Language:                 en_US
Permalink Structure:      /%postname%/
Active Theme:             Print Shop 14.0.1
Show On Front:            page
Page On Front:            Home (#1414)
Page For Posts:           Current Specials (#2996)
ABSPATH:                  /home/printstore/public_html/
Remote Post:              wp_remote_post() works
Table Prefix:             Length: 3   Status: Acceptable
WP_DEBUG:                 Disabled
Memory Limit:             40M
Registered Post Stati:    publish, future, draft, pending, private, trash, auto-draft, inherit, wc-pending, wc-processing, wc-on-hold, wc-completed, wc-cancelled, wc-refunded, wc-failed

-- WordPress Active Plugins

AddToAny Share Buttons: 1.7.7
Akismet Anti-Spam: 3.3
Another MailChimp Widget: 2.0.0
Checkout Files Upload for WooCommerce Pro: 1.1.1
Duplicate Post: 3.1.2
Enhanced Category Pages: 2.3.0
Force Regenerate Thumbnails: 2.0.6
Gmail SMTP: 1.1.1
Gravity Forms: 2.1.3
Gravity Forms Tooltips: 2.0.3
Nav Menu Roles: 1.8.6
Remove Yoast SEO Premium License Nag: 1.0.0
WooCommerce: 2.6.14
WooCommerce - Estimated Dispatch Date: 2.4.5
WooCommerce - Gravity Forms Product Add-Ons: 3.0.0
WooCommerce Direct Checkout: 1.1.2
WooCommerce Local Pickup Plus: 1.13.5
WooCommerce MailChimp: 2.0.20
WooCommerce Single Product Page Builder: 3.0.6
WooCommerce Square: 1.0.13
WP-Sweep: 1.0.10
WPBakery Visual Composer: 5.1
Yoast SEO: Local: 4.1
Yoast SEO: WooCommerce: 4.1
Yoast SEO Premium: 4.1

-- WordPress Inactive Plugins

-- Webserver Configuration

PHP Version:              5.6.25
MySQL Version:            5.6.35
Webserver Info:           Apache/2.4.23 (Unix) OpenSSL/1.0.1e-fips mod_bwlimited/1.4

-- PHP Configuration

Safe Mode:                Disabled
Memory Limit:             256M
Upload Max Size:          64M
Post Max Size:            64M
Upload Max Filesize:      64M
Time Limit:               300
Max Input Vars:           6000
Display Errors:           On (1)
PHP Arg Separator:        &

-- PHP Extensions

cURL:                     Supported
fsockopen:                Supported
SOAP Client:              Installed
Suhosin:                  Not Installed

-- Session Configuration

Session:                  Enabled
Session Name:             PHPSESSID
Cookie Path:              /
Save Path:                /tmp
Use Cookies:              On
Use Only Cookies:         On

### End System Info ###