Fixtures disappear after replacing with new symbol

[Stauba]

I have been having an issue lately. I received a file for a show, but I don't like the symbols they used. I'm going through and replacing their symbols with the symbols I like. I have done this in the past with no issue. I'm coming into this problem. When I replace the fixture on the design layer it shows up just fine, but once I exit out of the editing page it disappears. I can see the unit number and the channel number but not the fixture. If I mouse over it I can see the symbol as a grey dashed line, but can't see the actual thing. 

 

Has anyone else come across this? What am I doing wrong?

 

 

[Pat Stanford]

Most likely your replacement symbols are using classes that did not exist in the file when you created the viewports. By default new classes are usually set to Invisible in viewports.

 

Either check the Classes... button in the OIP for each viewport or go to the Organization Pallette, Viewports tab and choose Visibilities in the upper right. Select all the viewports you need and you can set the visibilities of layers and classes for multiple viewports at once.