Block References Itself *Invalid*

[kane333]

Hi Everyone,
First Timer here and somewhat New User to AutoCad (3 Months). I'm using AutoCad 2008 for Design/Build with a Mechanical Company. I use alot of Blocks for Pipe Fittings from Charlotte Pipe and Foundry in the design stage and occasionally, I'll have to manipulate or edit one of the blocks to get the 2D view I need. After "Save As" (for example from '2 inch Sanitary Tee Front View' to '2 inch Sani Tee Top View') I try to insert the newly named block into my drawing but get the error message "2 Inch....Block References Itself *Invalid* and it won't load the block. Even opening a new drawing tells me the same error message. What am I doing wrong?

[tedg]

Hi Everyone,
First Timer here and somewhat New User to AutoCad (3 Months). I'm using AutoCad 2008 for Design/Build with a Mechanical Company. I use alot of Blocks for Pipe Fittings from Charlotte Pipe and Foundry in the design stage and occasionally, I'll have to manipulate or edit one of the blocks to get the 2D view I need. After "Save As" (for example from '2 inch Sanitary Tee Front View' to '2 inch Sani Tee Top View') I try to insert the newly named block into my drawing but get the error message "2 Inch....Block References Itself *Invalid* and it won't load the block. Even opening a new drawing tells me the same error message. What am I doing wrong?

It's usually due to the fact that you have a block definition (block name) in the drawing file with the same name (a block within a drawing you're trying to insert as a block).

You need to do one of two things:

1. Explode the block and purge the name in your new block drawing file.
2. Rename the block definition inside your new block drawing file.

Option 2 will result in a nested block, if you insert the new block drawing file, you should explode it on insertion so you have just one block definition.

(my two cents)

[jaberwok]

Ted's right but I'd suggest that you use his option 2 not option 1.
Option 1 could lead to you having two blocks (the original and your modified version) with the same name in one drawing - this will lead you into another problem.

[tedg]

Ted's right but I'd suggest that you use his option 2 not option 1.
Option 1 could lead to you having two blocks (the original and your modified version) with the same name in one drawing - this will lead you into another problem.

Good point jaberwok, my "option 1" could result in you accidentally redefining your original block that you mean to keep.

The bottom line is your new (different) block should be a different name when you bring it in along side your existing blocks you want to keep.

...If not you'll have problems like redefining your existing blocks, or your intended "new" block doesn't show up as new because it's taking on the properties of the existing blocks with the same name.

(sorry for being so wordy...need to back off on the coffee)

[kane333]

What I don't understand is, I save the modified Block under a new name, copy/paste it into my Tool Palette, yet the error occurs even if I open a new drawing that has no blocks in it what-so-ever. When I use the 'Insert - Block' pull down is when it gives me the error, but I can drag that same block from my Tool Palette into the same drawing that gives me the error message and it'll work....

[irneb]

What I don't understand is, I save the modified Block under a new name

Explain how you do this. Do you copy-n-paste it to a new drawing or do you WBLOCK it out to a new file. Both scenarios could give you this problem, but the 1st is probably more prevalent.

When a block references it self, it means that it has a copy of itself nested within it. When you copy the block to a new drawing, it's placed inside that drawing as a block. Now when you insert that drawing, you're actually inserting 2 blocks in one go because you're inserting the entire drawing including the reference to the block you've pasted in it.

E.g. say the block's name is Block1. You copy it to a DWG file named Block1. When you now insert that file into another drawing it loads the file trying to generate a block definition named Block1, but it notices that one of the entities within this is also called Block1.

If you used the WBLOCK method, it would basically "explode" the block into the new drawing. BTW, this is the preferred method to generate a single block to a file. Unfortunately you can still end up with this error if you rename that file, since the block you "export" can contain nested blocks of other names - so you could have renamed the file to one of those. This would basically engender the same scenario as above.

Does the same thing happen if you use DesignCenter to extract the block from the file instead of inserting the entire file?

BTW, a quick and easy way of making a duplicate block with a different name in the same drawing is:

1. Use the RENAME command to rename the block;
2. Then select one of its instances & COPYCLIP (Ctrl+C);
3. Type U for undo twice (until Rename is undone);
4. Paste the copied version back into the drawing (Ctrl+V)

If you want to redefine one block with another, which is already in the drawing, use the Express Tool: BLOCKREPLACE (Express --> Blocks --> Replace block with another block).

[bruce.jones542083]

What I don't understand is, I save the modified Block under a new name, copy/paste it into my Tool Palette, yet the error occurs even if I open a new drawing that has no blocks in it what-so-ever. When I use the 'Insert - Block' pull down is when it gives me the error, but I can drag that same block from my Tool Palette into the same drawing that gives me the error message and it'll work....

Y'll,

It has been my experience that when I get that error, I have a block (lets say it is called "A") within the block of the same name, "A" (often happens when you explode and modify an existing block). To avoid this, once I have exploded a block I do a PURGE, then fix and resave my block. When you insert it again it should be clean. You sometimes have to explode your original block two or more times. AutoCAD will let you create these same-name blocks within blocks, but it gets nuts when you try to insert them.

Bruce

[Diznae]

Very new to AutoCAD but very interested to see what appears to be a very frustrating problem so is there any way you can clean a Block up so that it stops references itself *Invalid*

[irneb]

While all those "methods" to "fix" such blocks help ... I still believe the problem is that people don't get trained enough in what a block actually IS. This because it's probably the single biggest mistake new acad users make (at least from my experience of the last few decades). If they knew this, they'd realize that WBlocking out an inserted block / copy-pasting an insert into a new "block DWG file" is actually the same thing as attempting to lift yourself up using your shoelaces. And if they understand blocks to this level, such problems are very easily avoidable in the first place (actually easier than to do it the wrong way round).

To try and explain: A block is NOT the thing you see on the screen. It's the "definition" of what to display. This is saved inside the DWG as a non-visual (hidden) set of data stating what's inside the block. When you place the block, all that's being done is you create an Insert of the block, not the block itself - the very idea of a block is this: you have a definition which you can insert multiple times without duplicating anything.

The "error" happens when people fail to realize the difference between the 2, or more probably have not been shown what the difference is. They think that the thing they see IS the block, and thus if they export this visible thing (by whatever means) the exported DWG is the block and can be used in place of it. This is wrong because they're actually exporting the inserted block reference, which in turn exports both the definition and the insert/reference into that DWG. I.e. when you do this, you create a DWG which contains the block, but what you're actually after is a DWG which IS the block.

So rather than exporting the insert and then later trying to fix it, do it the "correct" way to begin with by forcing ACad to export the block's definition as a new DWG. The "easiest" way to do this is also the oldest - using the WBlock command, but ensuring you use it's "Block" option when in the dialog (NOT its "Objects" option). Quick check: If you have to type the block's name when saving the file, then you're doing it wrong. If this happened, you're making a nested copy of the block inside a DWG by the same name - which will then fail to insert as it will have a block within a block, both named the same.