[Mathias]

I'm not very familiar with the 4e files, but if you're creating themes, you may have made changes to the styles_ui.aug and system_resources.aug files.

I've looked at the diffs for those files in recent changes.

In styles_ui.aug:
This:

  <!-- style used on delete actions - bitmap-only with no text -->
  <style
    id="actDelete">
    <style_action
      textcolorid="clraction"
      font="fntactsml"
      up="actdelup" down="actdeldn" off="actdelof">
      </style_action>
    <resource
      id="actdelup"
      isbuiltin="yes">
      <bitmap
        bitmap="delete_small_up.bmp"
        istransparent="yes">
        </bitmap>
      </resource>
    <resource
      id="actdeldn"
      isbuiltin="yes">
      <bitmap
        bitmap="delete_small_down.bmp"
        istransparent="yes">
        </bitmap>
      </resource>
    <resource
      id="actdelof"
      isbuiltin="yes">
      <bitmap
        bitmap="delete_small_off.bmp"
        istransparent="yes">
        </bitmap>
      </resource>
    </style>

Became this:

  <!-- style used on delete actions - bitmap-only with no text -->
  <style
    id="actDelete">
    <style_action
      textcolorid="clraction"
      font="fntactsml"
      up="deletesmup" down="deletesmdn" off="deletesmof">
      </style_action>
    </style>

In system_resources.aug this was added:

  <!-- small delete buttons -->
  <resource
    id="deletesmup"
    issystem="yes"
    isbuiltin="yes">
    <bitmap
      bitmap="delete_small_up.bmp"
      istransparent="yes">
      </bitmap>
    </resource>
  <resource
    id="deletesmdn"
    issystem="yes"
    isbuiltin="yes">
    <bitmap
      bitmap="delete_small_down.bmp"
      istransparent="yes">
      </bitmap>
    </resource>
  <resource
    id="deletesmof"
    issystem="yes"
    isbuiltin="yes">
    <bitmap
      bitmap="delete_small_off.bmp"
      istransparent="yes">
      </bitmap>
    </resource>

And this was added:

  <!-- **********   ENCOUNTER BUILDER   ********** -->

  <resource
    id="missourdn"
    issystem="yes"
    isbuiltin="yes">
    <bitmap
      bitmap="missing_source_down.bmp"
      istransparent="yes">
      </bitmap>
    </resource>
  <resource
    id="missourup"
    issystem="yes"
    isbuiltin="yes">
    <bitmap
      bitmap="missing_source_up.bmp"
      istransparent="yes">
      </bitmap>
    </resource>

  <resource
    id="misimpdn"
    issystem="yes"
    isbuiltin="yes">
    <bitmap
      bitmap="missing_source_important_down.bmp"
      istransparent="yes">
      </bitmap>
    </resource>
  <resource
    id="misimpup"
    issystem="yes"
    isbuiltin="yes">
    <bitmap
      bitmap="missing_source_important_up.bmp"
      istransparent="yes">
      </bitmap>
    </resource>

  <resource
    id="plus_of"
    issystem="yes"
    isbuiltin="yes">
    <bitmap
      bitmap="plus_of.bmp"
      istransparent="yes">
      </bitmap>
    </resource>
  <resource
    id="plus_dn"
    issystem="yes"
    isbuiltin="yes">
    <bitmap
      bitmap="plus_dn.bmp"
      istransparent="yes">
      </bitmap>
    </resource>
  <resource
    id="plus_up"
    issystem="yes"
    isbuiltin="yes">
    <bitmap
      bitmap="plus_up.bmp"
      istransparent="yes">
      </bitmap>
    </resource>