T-Mobile subscribers are having problems sending text messages and receiving phone calls, according to WCCO.

T-Mobile’s official Twitter account says the company is aware of the disruption and has sent teams out to fix it.

WCCO reported that this could be the second black eye for T-Mobile, a unit of Deutsche Telekom AG, in less than a month. In October, a server failure caused customers with Sidekick-brand phones to lose much of their data.