MakeOTF error when reopening .otf-file: locl catalan & dutch

Hello, I made a font containing locl features for CAT and NLD,
both features are working as supposed inside the .glyphs file , and also when testing exported .otf fontfiles in InDesign.
But when reopening the previously exported .otf fontfile in glyphsapp 2.6.2 (1240), the features menu in the lower left corner of edit view ist flagged. When I open the features tab and try to update all the features the following MakeOTF error appears:

I found out after deleting the lines 11, 12, 23 and 24, I can update the features and everything works fine (obviously besides locl KAT and NLD).
and this is how lookups 8 and 9 look like:

10 29

As mentioned above the features are working well in »real life«, but I feel a little uncomfortable having an error message when opening my files in glyphsapp, so I wonder what could be the reason for this.

Importing a binary and reconstructing the feature code is not easy and not always possible. So opening a file in Glyphs to see what is in the GSUB table is by not a good idea.

Ok, thank you.
It was not my intention to see what is in the GSUB table, just realised the features were not working at all, so i tried to eliminate the lines that caused the error to find out where the problem might come from.
At least now i know there must be something wrong with locl CAT and NLD in the .glyphs file.
As all of the locl features have been auto-generated, i’m wondering what else I might have done wrong and will have a look in the locl tutorials one more time.

Which problem? You said the font was working? It’s unlikely a reverse engineered OTF will compile out of the box. What counts is if everything is going well with the original .glyphs file.

Yes, the font is working. But I have not experienced a similar situation (none of the features working) before when opening other .otf files. MakeOTF error made me curious and I think it would not show up if there was not at least some kind of »problem« in the original .glyphs file.