Layers switching off.

[Anonymous]

Some of my layers are being switched off by AutoCad. Is there a reason for this?

[cadffm]

Autocad usually does not switch layers.
Are they system layers or your own layers?

When does it happen?

Do you have Autodesk Autocad or another product?

Without the answers, I guess first you're using an add-on program which creates this problem.

Like Script.scr or macros.

You speak of layer on / off, do not mean freeze / thaw in current Viewport?

[pendean]

Let me guess: these layers are part of an XREF or XREFs you have in the file?
You control that setting in the top file, its called VISRETAIN, look up usage in HELP.

[Anonymous]

Hi Sebastian, thanks for getting back to me. I'm using an official copy of AutioCad LT. The layers that turn themselves off were created by me. I think the drawing may be corrupt. It has happened before but today it seems to have gotten worse. The layers switch off in model space and therefore can't be seen in the viewports. It's just frustrating as I sometimes feel I have accidentally deleted a layer.

[h_s_walker]

Do an AUDIT of the drawing. Say YES to fixing any errors. Switch your layers back on. Save your drawing. Close and then reopen the drawing. Are the layers on or off?

[Anonymous]

I usually do an Audit every so often anyway. Just did as you suggested and still no joy.

[h_s_walker]

Can you post a basic drawing with the layers in it.

[Anonymous]

Sorry, not allowed to.

[pendean]

AutoCAD on its own NEVER changes the state of a layer.

So you are doing it: are these layers in an xref?
Are you using VIEW command to call views?
Are you running a script file that manipulates layer settings?
Are you using LAYOFF or LAYFRZ and not noticing the actions?
Are you using LAYWALK command? LAYISO command?

Are others in your office working in the same files?

Try to answer these hard questions we are asking, not just the easy ones. If you don't know the answers, try to find out.

[h_s_walker]

Start a completely blank drawing, with no layers or anything in it.

Use Designcenter to import the layers into this drawing. Make sure the layers are turned on.

Save the drawing, close and reopen it. Are the layers on or off?