I posted about it in IRC, but you may see this first, so I'll post it here.
[20:47:02] <@Anna> Hm
[20:47:09] <@Anna> Attempting to convert this .shp didn't work
[20:47:21] <@Anna> Maybe the version of Shipmaker I used was incompatible
[20:49:07] <@Anna> Hm
[20:49:18] <@Anna> Well, the .sb4 opens fine in the last official shipmaker release
[20:50:12] <@Anna> It's not converting.
[20:50:37] <@Anna> Maybe it's 'cause I'm using custom colours idk
[20:53:24] <@Anna> This is just straight up not working
[20:53:32] <@Anna> I'm pressing F9
[20:53:37] <@Anna> I am selecting a .shp file
[20:53:47] <@Anna> I am typing in a filename to save the .json as
[20:53:51] <@Anna> But then nothing happens
[20:53:56] <@Anna> No .json files are created
[20:54:16] <@Anna> Wait
[20:54:17] <@Anna> one set
[20:54:37] <@Anna> Nope, still no work
[20:55:47] <@Anna> I am completely fuckin mystified
[20:59:56] <@Anna> th15
[21:00:08] <@Anna> Can you see any reason why this ship would not convert?
[21:02:22] <@Anna> Has only Stock 1-18 sections, has only pulse guns, particle guns and blasters as weapons, has no custom colors, has no custom anything, was made in the last official BSF release build
[21:02:24] <@Anna> so I am
[21:02:26] <@Anna> confused
[21:05:37] <~Arcalane> I think he already went to bed
[21:05:55] <@Anna>I can't even get it to convert this
[21:05:57] <@Anna> argh
[21:07:52] <@Anna> Yeah no
[21:08:09] <@Anna> The shp->json conversion doesn't work at all for me
[21:08:44] <@Anna> Making ships in barebones .90d Shipmaker
[21:08:49] <@Anna> And still no conversion
[21:08:53] <@Anna> So
[21:08:55] <@Anna> That's a thing
EDIT: Problem has been fixed. The .json must be saved to a different folder from the one you have the game installed in. This is really weird, but fixes the problem for now, for anyone else who wishes to convert ships and see how they work.