Warning message

I have this message appear :

<span style=”box-sizing: border-box; font-weight: bolder; color: rgb(51, 51, 51); font-family: -apple-system, "system-ui", "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif; white-space-collapse: collapse;”>Warning</span><span style=”color: rgb(51, 51, 51); font-family: -apple-system, "system-ui", "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif; white-space-collapse: collapse;”>: Undefined array key “gc_event_timezone” in?</span><span style=”box-sizing: border-box; font-weight: bolder; color: rgb(51, 51, 51); font-family: -apple-system, "system-ui", "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif; white-space-collapse: collapse;”>/home/clients/469cfb64c90b7546ea3ab2fc3007b2c6/new/wp-content/plugins/events-calendar-for-google/includes/class-ecfg-template-functions.php</span><span style=”color: rgb(51, 51, 51); font-family: -apple-system, "system-ui", "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif; white-space-collapse: collapse;”>?on line?</span><span style=”box-sizing: border-box; font-weight: bolder; color: rgb(51, 51, 51); font-family: -apple-system, "system-ui", "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif; white-space-collapse: collapse;”>95Warning</span><span style=”color: rgb(51, 51, 51); font-family: -apple-system, "system-ui", "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif; white-space-collapse: collapse;”>: Trying to access array offset on value of type null in?</span><span style=”box-sizing: border-box; font-weight: bolder; color: rgb(51, 51, 51); font-family: -apple-system, "system-ui", "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif; white-space-collapse: collapse;”>/home/clients/469cfb64c90b7546ea3ab2fc3007b2c6/new/wp-content/plugins/events-calendar-for-google/includes/class-ecfg-template-functions.php</span><span style=”color: rgb(51, 51, 51); font-family: -apple-system, "system-ui", "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif; white-space-collapse: collapse;”>?on line?</span><span style=”box-sizing: border-box; font-weight: bolder; color: rgb(51, 51, 51); font-family: -apple-system, "system-ui", "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif; white-space-collapse: collapse;”>9</span>5

I didn’t change anything and all my plugins are updated…

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