Why the newly-created objects have disappeared?

Sometimes the newly-created object would disappear when we have just created it, how does this happen?

1. Color setting problem

Generally, if the color of object is the same as or close to the background color of graphics window, the color will be changed or inverted. For instance, if the background color is yellow and the object is also yellow, from the following prompts we can know that we are actually drawing a circle, but we just can’t see it, as shown in the following picture,

When we press CTRL + A, we can see there is indeed a circle in the graphics window, as shown in the following picture,

To avoid this, please do not use object color that’s similar to or the same as the background color.

2. Layer setting problem

Newly created objects are on the current layer, although layers can be on/off/freeze/locked, the current layer can be off but can’t be frozen.

If the current layer is off, the newly-created objects can be seen while drawing, as shown in the following picture,

But after specifying the radius or diameter of circle, the circle has disappeared. It can be selected if we press CTRL + A, as shown in the following picture,

So if the newly-created object disappears, check the layer setting.