Thanks for reaching out and thank you for using GridOne theme with BoldGrid Post and Page Builder for WordPress!
I’m sorry to hear you’re having trouble viewing your events list from your admin area. This is hard to diagnose because I don’t have access to your dashboard to inspect. My theory is that a recent update is causing the something to clash either with Your “GridOne” V1 theme or maybe even the Events plugin or WordPress itself.
Have you recently updated WordPress Core, Your GridOne theme, or any plugins that you think may be contributing to the error? We should start there if we can narrow down the cause you could use a possibly use a plugin like WP Rollback to rollback to version updates and restore functionality.
We look forward to assisting you further with this!