Blank MailPoet Admin Pages
If the MailPoet pages (Settings, Emails, Subscribers, etc) in your wp-admin dashboard are displaying blank pages, this is usually caused by either 1) something in your browser blocking the pages from loading as expected, or 2) a conflict with other code running on the site (in another active plugin or the active theme).
Browser
We have received reports of "blank admin pages" that were traced back to browser extensions/plugins like ad-blockers, security, or user snippets that were blocking plugin files from loading as expected, causing pages to display incorrectly.
As a first step in troubleshooting this, we recommend checking in an incognito/private browser window with extensions disabled, or a completely different browser without any add-ons running.
If the pages load as expected in the state above, then it would be necessary to narrow down which browser add-on is causing the issue by disabling them one-by-one and testing in between in your primary browser.
Code Conflict
If you are still seeing the same issue with all browser extensions disabled, then the issue is likely coming from a conflict with other code running on the site. In that case, a conflict test would be necessary. We have a guide for performing theme/plugin conflict tests here.