Diagnosis
Possible causes for this problem are:

• You are in the display mode and want to switch to the catalog screens,
although there are no entries on these screens.

• You are in the "Create" or "Change" mode and want to switch to the
dynamic modification screen, but dynamic modification is defined at lotlevel in the task list header.

• You are in the "Create" or "Change" mode and want to switch to the
screen for quantitative data, although the indicator selected was for aqualitative characteristic.