I recently have been running into a problem where my authoring tools will close but steam will not recognize it. Leaving me to not be able to open it again.

I have tried restarting steam and looking through my processes but I couldn't find anything.

Has anyone else had this problem?

I haven't had that particular problem, although I don't use the tools. Create a desktop shortcut for hammer:

"C:\Program Files (x86)\Steam\steamapps\common\portal 2\bin\hammer.exe" -nop4

When this happened to me I just restarted my computer.

The problem went away but it's not really much of a fix.

Ciirulean wrote:
When this happened to me I just restarted my computer.

The problem went away but it's not really much of a fix.

I did exactly that. It fixed for what it is worth. Thank you!