Delete Undo Information (Edit Menu)

This command removes the current undo information from memory. Undo information is generated every time you carry out an operation which can be undone using the Undo command.

The size of the undo information depends on the number of objects which have been altered at the same time. If a large number of objects have been altered, then a memory bottleneck can arise. In this case, you should consider erasing the undo information.

The larger the maximum number of undo levels, the more undo information is generated. If you often get memory shortages when working with large numbers of objects, then you should either increase the available object memory or reduce the number of undo levels (see Edit > Options > General).

The undo information needed to undo operations is not saved along with the drawing, i.e. it is lost when the drawing has been saved and is loaded again.