I’m using Inkscape, but if you have and know Illustrator, I’d keep using it. Inkscape has a number of quirks most of which I’m now used to, but any svg editor should do fine. On to your part: my copy of the script (which is a development version not yet released) finds a fair number of errors. Starting with the pcb svg (because that was the last complaint 
), you are missing the silkscreen layerId which is what is causing one of the “Found a drawing element before a layerId (or no layerId)” messages. The first group (Inkscape added a made up groupId, the original file has no id in this group in the xml (as usual I can’t get the forum preformatted text function to work correctly)
< /desc>
< g>
<rect
stroke-width=“1”
fill=“none”
stroke-miterlimit=“10”
width=“36.8”
stroke="#231815"
height=“39.5”
/ >
needs an
id=“silkscreen” in it to set the layerId correctly.
schematic needs a group with id=schematic (there will be another complaint about drawing element before layerId about that). The terminalIds are still missing as well which will cause the wires to connect in the middle of pin rather than the end. The scale is a bit wrong too. The drawing dimensions are in inches (not px) so that should be OK, but the lines don’t align on .1inch boundaries which will be why it is not aligned with the grid in schematic in Fritzing. You need to move the lines up and for the veritcal ones across so they align on .1 inch boundaries. The you need to add a .01in by .01 rectangle named connector0terminal and position it on the end of the line for the connector. Once you add the rectangle parts editor will put it in the right place with the set the east/west/north/south settings (I have never been able to get it to work and just edit the svg, but other people use parts editor to do this). If you like I can fix the schematic svg up and post a copy so you can see what needs to be done. You have managed to fix the height/ width in px warnings, all the svgs are set correctly in “inches”. The warning is referring to the first element in the xml (this is from schematic):
“svg
xmlns=“http://www.w3.org/2000/svg”
x=“0px”
y=“0px”
viewBox=“0 0 39.5 39.2”
id=“レイヤー_1”
baseProfile=“tiny”
width=“0.548611in”
version=“1.2”
gorn=“0”
xml:space=“preserve”
height=“0.544444in””
if height said
height=“0.544444”
or
height=“0.544444px”
then you will get the warning and Fritzing may guess wrong and screw up your scale. As I said these 4 svgs are all correctly set to inches and should be fine, other than schematic may have been converted to inches when the scale was wrong, as its scale is currently off.
Peter