Latest Update Crashes Site

Your Version 6.3.0 latest update now crashes our website. I had to deactivate the plugin to maintain the site from crashing. The error message reads:

This plugin failed to load properly and is paused during recovery mode:
An error of type E_PARSE was caused in line 253 of the file /var/www/vhosts/greatpaperstraws.com/httpdocs/wp-content/plugins/simple-sales-tax/includes/class-sst-ajax.php. Error Message: syntax error, unexpected ‘)’

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