Dynpro is too big; maintenance size cannot be changed

What causes this issue?

The screen contains more than 20 lines. This may occur if, for example,
it has been trnasported from an R/2 system.

System Response

The screen is executable in this form but the window size is not
automatically adjusted in the process.

How to fix this error?

In the layout editor (F5), you can rearrange fields and delete lines in
the top part of the screen. Lines above 20 are thus shifted up.

Error message extract from SAP system. Copyright SAP SE.