CSSStyleDeclaration Error after enqueueing email

I have a scheduled task that is supposed to send a summary email. The code is as follows:

	def send_email(self):

		email_args = {
			"recipients": self.email_to,
			"sender": None,
			"subject": self.get_subject(),
			"message": self.get_message(),
			"now": True,
		}
		enqueue(method=frappe.sendmail, queue="short", timeout=300, is_async=True, **email_args)

If I use bench console to run the function, I get the following error:

In [1]: my_app_name.pvt_tasks.daily()
ERROR   PropertyValue: Missing token for production Choice(ColorValue, Dimension, URIValue, Value, variable, MSValue, CSSCalc, function): ('HASH', '#0000001a', 1, 3215)
ERROR   PropertyValue: Unknown syntax or no value: 0 3px 6px #0000001a
ERROR   CSSStyleDeclaration: Syntax Error in Property: box-shadow:0 3px 6px #0000001a

The error occurs even if the message string is is “Hello”. There are no email_css hooks in my app.

Pls help

The error does not occur if the frappe core email.bundle.scss is edited and the lines box-shadow:0 3px 6px rgba(0, 0, 0, 0.1) is changed to box-shadow:0 3px 6px 0
But editing the frappe core must not be the solution.

I created an scss file for my app and linked it with email_css='my.bundle.scss' in my app’s hook.py. The scss file contains:

.screenshot {
	box-shadow: 0px 3px 6px rgb(0, 0, 0);
}

it is still not working - am getting the error.

sites/assets/frappe/dist/css/email_bundle_HASH_.css file manually