I just updated my Spine Editor and Runtimes to the latest version (3.4.02, up to commit 94dcbf4125d52804bb2b0b6952f199b4322f02d0), re-exported all models, and now I'm getting an exception whenever I try to load any model that has indexed names, such as leg_left_02 or segment_1.

Caused by: com.badlogic.gdx.utils.SerializationException: Error reading attachment: leg_left_02, skin: default
   at com.esotericsoftware.spine.SkeletonJson.readSkeletonData(SkeletonJson.java:248)
   ... 23 more
Caused by: java.lang.RuntimeException: Region not found in atlas: leg_left_02 (region attachment: leg_left_02)
   at com.esotericsoftware.spine.attachments.AtlasAttachmentLoader.newRegionAttachment(AtlasAttachmentLoader.java:49)
   at com.esotericsoftware.spine.SkeletonJson.readAttachment(SkeletonJson.java:304)
   at com.esotericsoftware.spine.SkeletonJson.readSkeletonData(SkeletonJson.java:245)
   ... 23 more

In this case, this is how my skeleton.atlas looks like:

skeleton.png
size: 1024,1024
format: RGBA8888
filter: Linear,Linear
repeat: none
body
  rotate: false
  xy: 1, 66
  size: 625, 916
  orig: 625, 916
  offset: 0, 0
  index: -1
leg_front
  rotate: false
  xy: 628, 771
  size: 220, 211
  orig: 220, 211
  offset: 0, 0
  index: 1
leg_front
  rotate: false
  xy: 628, 480
  size: 136, 289
  orig: 136, 289
  offset: 0, 0
  index: 2
leg_front
  rotate: true
  xy: 244, 13
  size: 51, 215
  orig: 51, 215
  offset: 0, 0
  index: 3
leg_left
  rotate: true
  xy: 628, 260
  size: 218, 131
  orig: 218, 131
  offset: 0, 0
  index: 1
leg_left
  rotate: false
  xy: 628, 62
  size: 198, 196
  orig: 198, 196
  offset: 0, 0
  index: 2
leg_left
  rotate: true
  xy: 1, 1
  size: 63, 241
  orig: 63, 241
  offset: 0, 0
  index: 3
leg_right
  rotate: true
  xy: 850, 765
  size: 217, 152
  orig: 217, 152
  offset: 0, 0
  index: 1
leg_right
  rotate: false
  xy: 766, 532
  size: 52, 237
  orig: 52, 237
  offset: 0, 0
  index: 3
leg_right
  rotate: false
  xy: 820, 552
  size: 134, 211
  orig: 134, 211
  offset: 0, 0
  index: 2

Shouldn't Spine look for leg_left, index 2 instead of leg_left_02?