btw, as you use a portable version anyways:

you could try out the portable version of notepad++ 7.6.3 from >>> here <<< extract it to a new folder, and update dspellcheck.
on 7.6.3 run `plugins > plugins admin > updates" and update dspellcheck to 1.4.9
(note: “plugins admin” is only available on portable notepad++ since version 7.6.2)

if dspellcheck is the cause of your issue, you can also update to dspellcheck 1.4.10 manually from >>> here <<< and retry.

if technical informations are of interest to you, you can re-read following dspellcheck issues, based on the research of @guy038 :
https://github.com/Predelnik/DSpellCheck/issues/139
https://github.com/Predelnik/DSpellCheck/issues/151

if you have DSpellCheck plugin installed an enabled on your notepad++:
please go to plugins > dspellcheck and disable (uncheck) spell check document automatically as seen at the screenshot below.
then retry expanding the same block on your file.

if you still experience the same issue with dspellcheck disabled:

uninstall dspellcheck completely (or temporarily rename your DSpellCheck.dll to DSpellCheck.bak)
restart notepad++ and retry expanding the same blocks on your file.

if all this does not work:
please tell us more about your file and your notepad++ setup.
(go to ? > debug info... > copy debug info to clipboard and paste it here.)