I had that happen at one time doing that and I don't know how I fixed it. I think I might have deleted it all and started from scratch. I don't know. ccbarr isn't on line very much but I know he could help you fix it but I would just start it over and maybe you might have missed one little step.

no, don't do that, it has to be exactly like ccbarr wrote.

Either delete it and start over or try posting your xcf in the attachment thing below. Maybe someone can figure out what caused the squares

I’ve got the same problem. The problem is step 11. The inbetween layers appear but they haven't been affected by the plugin called. They’re all still square.

I thought it might be because GAP is 2.6 and Gimp is 2.8 but it appears there isn't a 2.8 version.

Try disabling Single Window Mode (at the bottom of the Windows menu). GAP sometimes switches the display on you and you may be looking at a different image than the one that was modified.

I have tried disabling Single Window mode. I even tried importing the layers first. Nothing works. You get first and last but everything inbetween is ignored. I even tried using " Filter all images" the way another tutorial said to but when I did that only the first instance showed, after clicking "continue" nothing happened.

I think there is a genuine problem here.

The Map-Object plugin has been updated in Gimp 2.8 with two new toggles in the GUI ("Create new layer" and "Update preview live") which changes the format and size of the last-vals data stored by the plugin, but the GAP iterator for Map-Object has not been updated since Gimp 2.6.6.

When you run GAP Frames Modify>Apply filter on layer(s) and select plug-in-map-object, the plug-in runs okay on the first layer but the GAP iterator (which should invoke the plugin for each "tween" frame) then craps out with the following error on the Console:
ERROR: p_plug_in_map_object_iter stored Data missmatch in size 528 != 520
(The mismatch in size is simply the two new toggles introduced, each a 32-bit int.)

The GAP file plug_in_map_object_iter_ALT.inc needs to be brought up to date and GAP re-built for all platforms.

Does anyone know whether Wolfgang Hofer is still maintaining this code (even occasionally)? He hasn't made any updates on git.gnome.org since last July.

Thanks jontait2, I thought something like that might be the case when " filters/apply to all layers" cut out after the continue button was pushed as the blur filter in another tutorial using same method worked.

oh this one looks fun, i must give it a try gotta go install GAP now
my video frames modify step didn't modify my frames for some reason (I tried it twice and it only modified the first one) so I had to manually create 30 layers and map object each one of them.

Wolfgang lives in a region which does not have internet access (or at least it is extremely expensive). In the past he would send updates for GAP about once a year or so. Usually he would come out with a new version of GAP soon after each new GIMP release, but not much changed between GIMP 2.6 and GIMP 2.8 (and ffmpeg finally started providing release versions) so GAP did not need updating (except for this Map Object problem).

I took the liberty of submitting a bug report (and patch). I hope you do not mind.

That's fine by me, Saul!

Thanks Saulgoode and Jontait2 for helping to sort this problem.