urgent: I can't draw the line in a view, pls help

[cmrhm]

In a sample file, I can draw lines in one view, but in another view, I can't draw lines, or the lines won't being shown up. What kind of settings I am missing?

I checked visibility control and view template, nothing special? However I do see some strange things: in that view, when I use detail lines>line tool, the cursor is different.

Any suggestions?

[ToanDN]

What kind of view?

[barthbradley]

Could be 33 reasons.  Go through this list:  

https://www.revitforum.org/node/459

[cmrhm]

Guys:

Thanks for the support. I found out I drew outside of the crop region, that is the reason I can't see the line I drew.

So this issue is solved.