Undo the last operation

`Command` + `Z`

All hotkeys for Comsol 5 (MacOS)

Help and Documentation Display help for the selected node or window	`F1`
Help and Documentation Open the COMSOLDocumentation front page in an external window	`Command` + `F1`
Model Tree Rename the selected node, file, or folder	`F2`
Model Tree Disable selected nodes	`F3`
Model Tree Enable selected nodes	`F4`
Model Tree Delete selected nodes	`Delete`
Model Tree Collapse a branch in the model tree	`Arrow Left`
Model Tree Expand a branch in the model tree	`Arrow Right`
Model Tree Move to the node above in the model tree	`Arrow Up`
Model Tree Move to the node below in the model tree	`Arrow Down`
Model Tree Move to the previously selected node in the model tree	`Ctrl` + `Arrow Left`
Model Tree Move to the next selected node in the model tree	`Ctrl` + `Arrow Right`
Model Tree Select all domains, boundaries, edges, or points; select all cells in a table	`Command` + `A`
Model Tree Copy text in fields	`Command` + `C`
Model Tree Clear the selection of domains, boundaries, edges, or points	`Command` + `D`
Model Tree Find a search string	`Command` + `F` `check`
Model Tree New model	`Command` + `N`
Model Tree Open a model file	`Command` + `O`
Model Tree Print the contents of the plot window	`Command` + `P`
Model Tree Save a model file	`Command` + `S`
Model Tree Paste copied text	`Command` + `V`
Model Tree Redo the last undone operation	Ctrl+Shift+Z
Model Tree Undo the last operation	`Command` + `Z`
Model Tree Move a definitions node, geometry node, physics node (except default nodes), material node, mesh node, study step node, or results node up one step	`Command` + `Arrow Up`
Model Tree Move a definitions node, geometry node, physics node (except default nodes), material node, mesh node, study step node, or results node down one step	`Command` + `Arrow Down`
Model Tree Switch focus to the next window on the desktop	`Ctrl` + `Tab`
Model Tree Switch focus to the previous window on the desktop	`Ctrl` + `Shift` + `Tab`
Model Tree Switch focus to the Model Builder window	`Command` + `Alt` + `Arrow Left`
Model Tree Switch focus to the Settings window	`Command` + `Alt` + `Arrow Right`
Model Tree Switch focus to the previous section in the Settings window	`Command` + `Alt` + `Arrow Up`
Model Tree Switch focus to the next section in the Settings window	`Command` + `Alt` + `Arrow Down`
Model Tree Open the context menu	`Ctrl` + `F10`
Model Tree Open list of predefined quantities for insertion in Expression fields for plotting and results evaluation	`Ctrl` + `Space`
Build and Compute Update the Data Sets Solutions with respect to any new Global Definitions and Definitions without re-solving the model	`F5`
Build and Compute Build the preceding node in the geometry branch	`F6`
Build and Compute Build the selected node in the geometry and mesh branches, compute the selected study step, or compute the selected node in the solver sequence	`F7`
Build and Compute Build the geometry, build the mesh, compute the entire solver sequence, update results data, or update the plot	`F8`