Hello! Pardon my grammar because English is not my native language. I'm animating an animated emote and in the gif export, there's this weird line at the edge of the gif (the hair part, our right side). There's no such outline in the file itself, nor in the PNG sequences.
I even tried combining the PNG sequences and reexporting them to gif again... and the outline just pop up in the gif. Is this a bug? Is there any way to solve it? Thank you!
Weird extra stuff on gif export
Screenshots of the PNG sequences. The weird outline is not inside here. It's not the gif viewer problem, I tried uploaded it on Discord and the outline does exist. 
Sapphire Sorry for the trouble. That is really weird. If you don't mind, could you please send your Spine project via email so that we can reproduce the problem on our end?: contact@esotericsoftware.com
Hello, Misaki! Thank you for the reply! I have emailed the file to your team.
Sapphire Thank you for sending your Spine project! I have confirmed the problem can be reproduced on my end. The cause is not yet figured, but as a workaround, changing the FPS setting seems to solve the problem. For example, if you change the Timeline FPS to 30 in the Playback view, this problem will not occur. Conversely, this problem can be avoided as well by changing the FPS in the export settings to 20 or 30 even if you leave the Timeline FPS as is.
I will create an issue ticket for this problem after some testing.
Ok, noted! Thank you!
An issue ticket for this problem has been created here:
EsotericSoftware/spine-editor739
@Sapphire You can subscribe to the issue ticket, then you will receive additional notifications upon any progress. Thank you for your report!
a month later
Hello! I have tested it out, yes it has been solved now, thank you!
I'm glad to hear that! Thank you for getting back to us!