Image forming apparatus for displaying a screen to prompt a user to re-attach a container having developing material

An image forming apparatus comprising:

• an image former configured to form an image with a developing material;
• a sensor configured to detect the developing material in the image former;
• a portion to which a container is attached, the container containing the developing material;
• a processor configured to:
• control replenishment operation in which the developing material is replenished to the image former from the container attached to the portion;
• and
• determine a replenishment error of the container based on the detection result by the sensor;
• and
• a display configured to:
• display a warning screen to prompt a reattachment of the container detached from the portion, in a case where (a) the container is detached from the portion and (b) a replacement condition is not satisfied;
• and
• display a discharge failure screen to notify of the replenishment error, in a case where the replenishment error is determined by the processor,
• wherein the display displays the discharge failure screen, in a case where (c) the container is detached from the portion, (d) the replacement condition is not satisfied, and (e) the replenishment error is determined by the processor.