Since this is occurring in beta2 and looks very much like a script error that existed 3.5.x -> 3.6.2 LibO (in OOo/AOO as well) and there is a similar regression on Bug 58269... if confirmed this is quite possibly a regression of that issue -- see Bug 58269.  

@ Paolo:  
Have you tried to uninstall/reinstall the Immagini extension? 
I tried to find a source for Immagini and could not.  
Can you please provide a source for (or a copy of) the extension?
(via google translate)
Hai provato a disinstallare / reinstallare l'estensione IMMAGINI?
Ho cercato di trovare una fonte per IMMAGINI e non poteva.
Si può fornire una fonte di (o una copia) l'estensione?

(In reply to comment #1)
> 
> @ Paolo:  
> Have you tried to uninstall/reinstall the Immagini extension? 
> I tried to find a source for Immagini and could not.  
> Can you please provide a source for (or a copy of) the extension?
> (via google translate)
> Hai provato a disinstallare / reinstallare l'estensione IMMAGINI?
> Ho cercato di trovare una fonte per IMMAGINI e non poteva.
> Si può fornire una fonte di (o una copia) l'estensione?

Until response -> NEEDINFO

hi.  sorry..  i am testing LO 4.0 RC1 with the same buttom 'web images' (but cannot say wether it is still an extension... it is not in the list) but now it works fine.  I copied a text with an image from an internet page and pasted it in a writer document. clicked 'web images', saved the document and closed writer. when I reopened the document the image was included and not linked.  no error message. I would say now it works and the bug can be considered solved.

actually I see it says 'image replaced' in the undo menu...  but am not sure it really works, will test when without internet connection, but it seems to work.

tested by unzipping the odt file.  image is correctly included.  problem solved.

confirmed. it is a macro contained in a package downloaded from the site 'istituto majorana' nothing else.  i don't know who has prepared it.

Dear Bug Submitter,

This bug has been in NEEDINFO status with no change for at least 6 months. Please provide the requested information as soon as possible and mark the bug as UNCONFIRMED. Due to regular bug tracker maintenance, if the bug is still in NEEDINFO status with no change in 30 days the QA team will close the bug as INVALID due to lack of needed information.

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Dear Bug Submitter,

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