Question:
Why does the "Undo" function only work for the last two or three steps (after that, it is grayed out)?
Answer:
When editing a model, it happens again and again that work steps just executed have to be reversed. However, how far you will be able to undo the executed work steps depends on the size of the buffer memory defined for them. In the case of a very large model with many loads and load combinations, the preset value is often insufficient.
Therefore, it is possible to customize the buffer size for the undo function in the "Program" tab of the Program Options dialog box.