Hello together
I have installed version 1.1.0 of Inkscape on my Mac Books running macOS 10.14.6, 10.5.7 and 11.4. In all three cases, when exporting a .sif file, I only get an empty file.

My procedure:
1. start Inkscape
2. draw a square with a blue fill.
3. save the drawing as .svg for Inkscape.
4. save the drawing as .sif (for Synfig Studio).

5. open the .sif file with a text editor and I see only the header of the file. The other XML data is missing.

<canvas version="0.5" width="793.700787" height="1122.519685" xres="2834.645752" yres="2834.645752" view-box="-6.614173 9.354331 6.614173 -9.354331">
      <name>Zeichnung.svg</name>
    </canvas>

What am I doing wrong?

Greetings, Jens.

P.S. In Windows 10 there is no problem with the .sif-Files.

I´m pretty sure we had exact this issue - but can´t find it and search didn´t help either. I can´t run Synfig under BigSur to check as it isn´t signed and dev can´t be verified - golden times.

Thanks for your answer. I searched allready, but found no hints. The problem is in Inkscape, not in Synfig. Because Inkscape write only the header of the file, but not all datas, as I show above. I have the problem on 3 (!) Macs with different macOS. 

Well after managing to open Synfig in BigSur it imports an Inkscape SVG with this error one time:

After that the SVG appears but outside the Synfig canvas, which was my fault:

So it seems to work from my understanding.

On windows I get that error in Synfig as well. But on my macs all exports of sif-files are still empty. I installed Inkscape more than one time. I have no ideas, why it is not working on my macs. :-(

Did you try to open or import? Both works here so far. I attached a sif exported file from Inkscape for you to test:

So, me again. I found the or two BUGs:

1. After every export as .sif I will get a new Icon in the dock of an closed Inkscape. Only with .sif-export. All other export do not start a new copy of Inkscape. I found that in macOS 10.14.6, 10.15.7 and 11.4.

See picture in the Archiv.zip.

2. ONLY when I create a drawing with a square or a circle and save this as .sif, the sif-File contains only the header, but there are NO data like <layer>...</layer> in it. – There is the bug!

See the files square.sif and cirlce.sif in the Archiv.zip.

3. All other drawing I found now are working correctly. When I add with a Bezier Curve to my square or circle, then the get a normal .sif file. 

So, now I know a way to solve it, until the next version of Inkscape. I will put the work around an my german website http://www.computergrafik-know-how.de as well.

Thanks for your help, greetings, Jens.

Ahoi Jens.

Could it be the circle is in a parametric condition and not a path and though not recognised in Synfig? Please convert with Object to Path first - then save as .sif

Ok, thanks for the tip. Convert-to-path works. Nevertheless, it is a bug, because either the user gets a warning, which is missing here(!), that the drawing contains circles and squares, or the programme silently converts circles and squares into paths. For a beginner with the program, the behaviour is incomprehensible.

Or Synfig expects paths exclusively - then it's up to you to make sure it  is. And because it is not an extra exporter, a "save as" is irreversible.

The automatic conversion of square and circle is part of the export / save in the PC-Version of Inkscape 1.1. Please add this also in the Mac-Version. Thanks. 

Feature requests can be made to the developers.

Info here:https://inkscape.org/forums/beyond/how-to-report-bugs-or-request-new-features/