Error in Template after nothing changed

[Cool_Jack]

Error 1 : Task 'New step' Body template. Expression 'Sum(<a id="_Int_xfpYqUB4" class="pt-000020"></a>Select(Formularantworten 2[Anzahl Neu], ([Haupt-Ort] = [_THISROW<a id="_Int_sfRCzZVS" class="pt-000020"></a>].[Haupt-Ort])))' is invalid due to: Expression 'Sum(<a id="_Int_xfpYqUB4" class="pt-000020"></a>Select(Formularantworten 2[Anzahl Neu], ([Haupt-Ort] = [_THISROW<a id="_Int_sfRCzZVS" class="pt-000020"></a>].[Haupt-Ort])))' was unable to be parsed: Sequence contains no elements..

that's my error after some hours makeing no changes to the template 

any ideas fot this error?

thanks.

[Steve]

Please post a screenshot of the template itself that includes the snippet referenced in the error message.