The most common cause of interface errors among the options provided is Duplex mismatch.
A duplex mismatch occurs when one device is set to half-duplex and the other device is set to full-duplex, which can lead to various network problems, including interface errors, degraded performance, and increased collisions.
While speed mismatch and buffer overflows can also contribute to errors, duplex mismatches are particularly prevalent in networking environments, especially when devices from different manufacturers are connected or after configuration changes.