Problems with Arabic marks in fontlab 7

I’m a designer not a type or a font developer. Learning font lab for windows (glyphs) does recognise us (windows) users as good enough designer. Anyhow, my problem is with damma is too high from the glyphs, I have spent many hours trying to workout a solution to this issue.
I also received this message (on exporting): WARNING: Glyph shadda_dammatan-ar: Not enough ‘t.fathatan-ar_1’ anchors for this ligature of 2 ligature components.
WARNING: Glyph shadda_fatha-ar: Not enough ‘t.fathatan-ar_1’ anchors for this ligature of 2 ligature components.
Not sure what is the problem here. I can send the font to anyone who can or willing to help.
I also cannot generate (mark), only generating (mkmk) from the features pannel.
Many thanks.

Mark positioning is done with anchors, mostly top and bottom anchors, in ligatures you would add an underscore followed by the number for each character, e.g. top_1 for the first letter and top_2 for the second. And the error message seems to suggest you are using an anchor only on one of the two letters of the ligatures.

Any particular reason you want to spell it out in feature code rather than with anchors?

Are you sure you are at the right forum? This is the Glyphs forum, not Fontlab?

Yes, many thanks for reminding me. Anyhow Mr [ Scheichelbauer] kindly explained what I was doing wrong. Appreciate your time. Thank you.

thank you. I will give it a try and see what the outcome. Wll let you know.