Schematic to PCB netlist sync problems

[peter.lee]

I am a relative newbie to Eagle. 

I am regularly having problems with loosing automatic sync between the schematic and PCB.  The latest one was to when I created some new net classes (track width and clearance) and then applied them to nets in the schematic.  I expected to see the netlist changes automatically reflected in the PCB but when switching I get an error indicating that the nets have different classes between the schematic and PCB.  Is there a way of forcing a netlist update to the PCB.

[one-of-the-robs · Accepted solution]

Did you obey the first rule of Eagle and ALWAYS HAVE BOTH EDITORS OPEN?

If you ever make any change to the schematic without having the board editor open at the same time, it will break things in exactly this way.

[peter.lee]

I have often seen the comments about always having both editors open at the
same time so I should have done. Having manually made both sides the same
it works as you would hope/expect it to. Maybe I had accidentally closed
one editor. Thanks for the input.