That's what I got after a custom battle:

18:02:29.265 [system.rpt] [always] CPU: SSE2
18:02:29.265 [system.rpt] [always] ==== system log start, build date: Feb 25 2008 version development ===
18:02:29.281 [system.io] [always] mounted pack packs/data_0.pack
18:02:29.281 [system.io] [always] mounted pack packs/data_1.pack
18:02:29.281 [system.io] [always] mounted pack packs/data_2.pack
18:02:29.281 [system.io] [always] mounted pack packs/data_3.pack
18:02:29.281 [system.io] [always] mounted pack packs/data_4.pack
18:02:29.281 [system.io] [always] mounted pack packs/localized.pack
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 45, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 46, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 47, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 48, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 49, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 50, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 51, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 52, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 53, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 54, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 55, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 56, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 57, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 58, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 59, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 60, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 74, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 75, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 76, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 77, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 78, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 79, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 80, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 81, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <label_unit>, at line 82, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
label_unit referenced non-existent unit
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit4'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit5'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit6'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit7'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit8'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit9'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit10'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit11'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit12'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit13'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit14'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit15'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit16'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit17'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit18'.
18:03:20.890 [game.script] [error] Script execution error for <define_unit_group>, at line 84, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit19'.
18:03:20.906 [game.script] [error] Script execution error for <define_unit_group>, at line 85, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit30'.
18:03:20.906 [game.script] [error] Script execution error for <define_unit_group>, at line 85, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit31'.
18:03:20.906 [game.script] [error] Script execution error for <define_unit_group>, at line 85, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit32'.
18:03:20.906 [game.script] [error] Script execution error for <define_unit_group>, at line 85, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit33'.
18:03:20.906 [game.script] [error] Script execution error for <define_unit_group>, at line 85, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit34'.
18:03:20.906 [game.script] [error] Script execution error for <define_unit_group>, at line 85, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit35'.
18:03:20.906 [game.script] [error] Script execution error for <define_unit_group>, at line 85, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit36'.
18:03:20.906 [game.script] [error] Script execution error for <define_unit_group>, at line 85, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit37'.
18:03:20.906 [game.script] [error] Script execution error for <define_unit_group>, at line 85, in mods/SS6.3/data/scripts/show_me/G5Script2.txt:
Error in battle script command 'define_unit_group': invalid unit label 'unit38'.

Is it normal, or am I to expect problems in the campaign?