Connecting letters and leading problems at export

Hello,
I have exported my arabic typeface a few times under many names to see how it works with all the diacritics and accents. The first two times I had no problem whatsoever but the last two the lines jumped over each other and I can’t figure out why. I didn’t change any of the metrics …
The second problem is connecting letters, as I saw in this tutorial on arabic letters https://vimeo.com/46216774 I added an entry and exit where it is necessary, but I still have white spaces between letters. (I think it’s because I named them Exit and Entry with capital E’s is that the problem?)

Here is a screenshot to be more clear:

Yes.

You don’t need anchors for this. Just fix the spacing of the glyphs.

To avoid the crashing of the lines, you need to increase the ‘Units per Em’. Just set it to 1300 and it should work.

The side-spacing was at zero for all connecting letters, I fixed the entry and exit anchors and it’s now working properly.

As for the Units per Em rescaling, that changes the glyphs’ size, so I decided to keep it as is (the problem in arabic type is that when the letters don’t have any added accents, the spacing is great, but once you add hamza and all the rest, things jump on top of other things and you need to increase the spacing, I will let users decide if they want to do so when they add accents, because it isn’t that common).

Thank you anyway !

one option is to add a alef-ar.short gives some room for the marks.

True, I will give that some thought

I’m still wondering, is there another way to fix the line clashing problem without reducing the glyphs’ size?

You can use a bigger upm or scale done the outlines.