Connection Lines on PCB - Rats nest display

Solution Details

Connection lines, or Rats Nest (ratsnest), display is controlled in more than a few ways:
 
The most direct way to turn on/off the display of all connection lines is to use the menu choice of the PCB editor:

• View ► Connections ► Show All  (or Hide All)

 
You can turn on/off individual connection lines from the PCB panel: 

• Select Nets view from the drop-down, then select <All Nets>. In the Nets section, double-click on a net to open the Edit Net dialog where you can verify the status of the "Hide Connections" checkbox.

Another place to look:

• View Configuration (panel) ► Layers & Colors (tab) ► System Colors (section) ► turn eyeball (visibility icon) on/off for Connection lines

 

To affect Single Layer Mode (Shift+S), check this:

• View Configuration (panel) ► View Options (tab) ► Additional Options (section) ► button for "All Connections in Single Layer Mode" on/off

 
If you are having trouble with connection lines, try:

• Design ► Netlist ► Clean All Nets

 
If you've tried everything above, and your connections lines still are not visible there is one other thing to check.  Open your PCB Panel and verify that the pulldown option at the top of this panel is *not* set to From-to editor.  If the PCB Panel is in this mode, it can only display connection lines for the from-to you are viewing or editing. 


Set this pulldown to any other option, such as Nets and your connection lines should again be visible. Here's documentation with more information on the From-To editor:
https://www.altium.com/documentation/altium-designer/pcb-pnl-pcbpcb-from-to-editor-ad

Here's documentation on "Managing the Display of the Connection Lines" where you can learn more (like keyboard shortcuts):
https://www.altium.com/documentation/altium-designer/creating-connectivity-ad#!managing-the-display-of-the-connection-lines