Bug with iframe during the email signing

From time to time in extension happens next error:

iframe:1 Uncaught (in promise) DOMException
Promise.then (async)
(anonymous) @ iframe:8
Promise.then (async)
(anonymous) @ iframe:8
Promise.then (async)
(anonymous) @ iframe:8
Promise.then (async)
(anonymous) @ iframe:8
signEmail @ iframe:8
(anonymous) @ iframe:1
u @ iframe:1

Error appear in the iframe from app.vereign.com (same happens with integration1, integration2, and other) during the sending email from GMail.