I am using indesign for my newspaper layout and my purple colum lines keep disappearing. Does anyone know how I can retrieve them?
A few things could be happening here. When you say they keep disappering do you mean when you make a new page? or are your pages already created with columns and for some reason while working on it the column guides dissappear?
If its the new page, go to your master page that is effecting your pages and just make the column guides on that. That way any new pages made will have the same guides as everything else.
If it's not that then go to View > Grids & Guides > Show Guides. If it says Hide Guide here skip this, it means this isn't the thing thats messing with your columns. The next thing we can do is go to you Tool Palette (the one with the arrows, pen, text and other tools on it. Down the bottom is a preview tool, right click on this and make sure it says normal.
Another possibility: If you are switching between views in ID from Normal to Preview Modes (key shortcut W), your guides are hidden in Preview mode.
As reported elsewhere here, there could be a number of possible causes at the root of your problem.
These are the three most likely causes for guides to suddenly disappear on you. If none of these are at the root of your issue, let us know and we can explore less-likely causes.
Hope this helps,