Old sxc calc file does not recognize formulas anymore

Hi,

I’m facing a problem when opening a sxc file, where formulas are not working. Instead they are show as textual value, eg. ooow:=SUM([.W102:.AH102])

This question is probably related to Calc Cells not calculating at all? but the solution given (adding office:class=“spreadsheet”> in the content.xml file does not work.

Looking at the cell in content.xml, I see this:

<table:table-cell table:style-name="ce1029" table:value-type="string" calcext:value-type="string"
   <text:p>ooow:=SUM([.W102:.AH102])</text:p>
</table:table-cell>

I’m using LO Version: 4.2.0.4 (Ubuntu).

How can I fix my file(s) ?

(also found an open bug report here: https://bugs.freedesktop.org/show_bug.cgi?id=69489)

It seems that the file was opened and saved with an intermediary version, which had the bug. Older version of the file can be opened just fine with 4.2.0.4