Eclipse : How to view all items of Errors under Problems View in Eclipse Editor

On Eclipse Helios click on the triangle pointing down on the Problems view, select Preferences then in the Preference dialog that appear, you can change the Limit visible items per group to change the value. Or else uncheck Use marker limits checkbox to allow all items being visible.

there is a triangle pointing down on the problems view, click on it, click configure contents, there will be "Number of items visible per groups:", change it

Just click on the arrow down in the Perspective and select Group by None.

or

Configure Contents...