"Cannot offset that object.". No reason given why not. (2014)

[Anonymous]

The worst part of this stupid bug that has existed for nearly 3 years, is that it shows me the location of the offset line, where it would be, but then just fails to create it.

Only solution I've found is to redraw the line. Which obviously only works if AutoCAD feels like making it work.

The Knowledge Centre recommends flattening the polyline. I've tried that. I've tried exploding it then re-joining it then offsetting it, no dice. I've tried offsetting it half the amount, with the intention of offsetting the created line again. Of course that doesn't work, that would be sensible.

The polyline has 12 vertices.

This thread has the same problem from 2012 and no-one managed to fix it (how to make the overkill command work is not stated, and it didn't work for me).

I know redrawing the line would have taken less time than creating this thread, and that's what I've been doing up until now. This must be the 20th time I've encountered this stupid bug.

Any ideas greatly appreciated

EDIT: Should mention the workaround i've always used is to copy the polyline into a new drawing, and then offset it, then copy it back. Yes I'm serious.

[dbroad · Accepted solution]

Cam,

Thanks for posting the drawing.  These are the issues and why you cannot offset.

1) The polyline appears to be closed but is not.  It has 9 verticies rather than 8.  That is why the offset has incomplete linework.  If the polyline is then closed by using the properties palette, it becomes an object with a 0 length segment, which cripples the object.

2)Fix:  Use the trim command.  Select the polyline as the cutting object and select the last segment as the object to be trimmed.  Then use the properties palette to close the polyline.  The closed polyline should have 8 verticies and 8 segments, not 9 verticies and 8 segments.  The fixed polyline should offset the expected manner.

In general, never close a polyline by selecting the first point manually.  Always use the close option and you will never end up with this issue.

[Patchy]

The problem is at the northwest corner of this shape, you have a zero length line.

Explode this shape, erase and pick all the Lines, do not window or crossing, you will see a dot left on the screen.

[Kent1Cooper · Accepted solution]

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cam01096 wrote:

.... 

The error came up again. I have a polyline that cannot be offset, please find it in the attached drawing.

This is the problem that comes up intermittently, and I'm not sure what causes it. Using the 3d-2d polyline lisp on it didn't work as apparently it's not a 3d polyline.

....

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I am able to Offset it inward, but not outward.  It is closed but has coincident vertices at the start/end, so it has, as with the earlier drawing when forced Closed via the Properties box, a zero-length segment that seems to be the cause of the problem.  You should be drawing these using the Close option from the [in the latest sample case] sixth vertex to make the closing segment, rather than picking again [for a seventh vertex] at the starting vertex location and then using the Close option.

Applying PLCL from the PLCloseCorner.lsp routine I linked to before [Post 17] fixes it.

[gccdesign]

I just had this happen for the first time. Tried to offset a rather complicated closed polyline and just got the error "Cannot Offset that Object". I was trying to do a 36" offset.

There are several posts and threads on this subject and I tried various things. I made sure the object wasn't too far from the drawing origin. I tried the World UCS. I checked for zero length segments. I tried the Overkill command, all with no success. Made sure it was leveled.

Then on a hunch I tried this. The polyline does have little notches and so on in it.

I tried an offset of 1" (instead of 36"). It worked. I tried an offset of 12". It worked. I made 3 successive offsets of 12" (which gave me my desired 36" offset) and it worked. 18" would not work. 16" would work.

So one fast way to work around this is to try a smaller offset that can be repeated a few times to add up to the desired offset. Then you could run overkill on the final offset if it's likely to have zero length segments by being reduced. Then delete the intermediate offsets. This is a fast way to deal with this.

This was done in Acad LT 2016, Win 8.1.

GChapp

[pendean]

Post your file with this object, indicate inside the file which side the object needs to be if you want others to provide additional input or feedback.

[gccdesign]

Here is a wblock of the polyline that won't offset. It won't offset 36", but it will offset 12".

Although my workaround I mentioned did take care of it in short order.

GChapp

[Patchy]

Offset 12, then offsset 24

Because

[gccdesign]

Yeah, I just did 12" 3 times, it was fast to do.

GChapp

[Anonymous · Accepted solution]

Once the pline in the posted drawing was properly closed it offset just fine.  

As others noted it was not properly closed, to repair use the PEDIT command:

PEDIT
Select polyline or [Multiple]: [select the offending pline]
Enter an option [Close/Join/Width/Edit vertex/Fit/Spline/Decurve/Ltype gen/Reverse/Undo]: E

Enter a vertex editing option
[Next/Previous/Break/Insert/Move/Regen/Straighten/Tangent/Width/eXit] <N>: B

Enter an option [Next/Previous/Go/eXit] <N>: N

Enter an option [Next/Previous/Go/eXit] <N>: G

Enter a vertex editing option
[Next/Previous/Break/Insert/Move/Regen/Straighten/Tangent/Width/eXit] <N>: X

Enter an option [Close/Join/Width/Edit vertex/Fit/Spline/Decurve/Ltype gen/Reverse/Undo]: C

Enter an option [Open/Join/Width/Edit vertex/Fit/Spline/Decurve/Ltype gen/Reverse/Undo]: [enter]

I'm suspecting OE may be the cause of other offset issues as well.

Plines are NOT lines any more than they are circles, they are PLINES.  And while I use plines a lot, I'm not quite sure why anyone would use them for everything.  I've been using plines since they showed up in the application and haven't had much issue with offsets unless the result attempts to bowtie a set of intersections or there are coincident vertices somewhere in the line.  Sometimes using smaller distances will help as it eliminates the bowtie effect by eliminating some vertices as they get very close together [taking out the notches in an earlier example].  Simple habits like; always using CLOSE to close a pline from the NEXT to last vertex, never ending a pline at the start point of the same pline, never tracing back over the same pline, keeping in mind your plan to offset a pline and avoiding small notches that might be an issue for offset, etc.

But hey, that's just me.

[Anonymous]

I have encountered this same glitch today on version 2017. Using some other designers base file, I attempted to draw a curvy POLYline for a driveway and was told it cannot be off-setted and no reason was given. by copy pasting the geometry back into my template file that I use every day it now magically works as it is supposed to. Autocad is often more magic than science. As someone who is 100% self taught on the software, I have learned that when AutoCad becomes obstinate or petulant, you must determine what the most annoying time consuming method for solving the problem and that will usually be the answer- not much reason in trying the easy stuff first (like zooming in to 1000X and checking all your vertices) just let the software punish you. 🙂

[modowdE4SBC]

I see this thread is from 2015... I get this issue all the time. Thanks for the copy-paste workaround, that's the only way I could fix it.

[cheryl.buck]

Hi @Anonymous,

I apologize for finding this thread so late, but wanted to share some information to help other members that might encounter the same issue. 

Being able to complete the OFFSET without issue in another drawing as you noted, indicates base file corruption. This is more common with files that have been reused many times and saved across multiple file formats. As this file was more than 10 years old at the time of the original post this seems likely to be the case. This information can be found using the DWGPROPS command. 

Generally, the solution for this type of corruption is to copy the geometry to a new drawing template, and not reuse affected files. Additional suggestions for file corruption can be found in: 

• How to repair corrupt AutoCAD files

All the best, 

[angel_diaz2FXZT]

Sometimes of the object has an elevation it won't let you offset it try setting elevation to 0. 

[angel_diaz2FXZT]

I would try setting the elation to 0 sometimes it doesn't let you offset because of that .