Endless typesetting with enabled Show changes in output

[racoon]

On 2020-02-26 11:03, Guido Milanese wrote:
> On Wed, 26 Feb 2020 07:29:31 +0100
> Daniel <xracoonx at gmx.de> wrote:
>
>> On 2020-02-25 21:45, Daniel wrote:
>>> Hi,
>>>
>>> I am trying to create a PDF that shows the changes I have done in a
>>> rather huge document. For some reason when I enable the option, the
>>> typesetting never ends. No error, no nothing. Just a message box
>>> after a while that the process is still running and whether I want
>>> to end it. No matter what I answer, it does not create the PDF.
>>>
>>> Daniel
>>>
>>
>> Sorry, forgot to attach the messages (below). But it doesn't tell me
>> much.
>
> I am not an expert in LyX (I normally use LaTeX directly) but I was
> wondering if this message:
>
>>   Different textclasses
>
> may be the clue. It seems that you are including files of "article"
> class in a parent document featuring the "scrbook" class. Perhaps this
> discussion may be useful:
> https://latex.org/forum/viewtopic.php?t=18594
> Just my tuppence.
>
> gm

Thanks. I have seen similar problems to those in the link encountered
before.

Unfortunately, I think that is not the culprit here. The message is only
a warning about possible inconsistencies between master and child
document, but I have now narrowed down my search for problems to one
child document where I get the endless typeset without having any other
documents involved.

Daniel