Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4.

I am very new to all this, can anyone help me understand how/where to find this error and fix it?

 

[Raidable Bases] RaidableBases\Difficulty_Loot\Normal --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4.
[Raidable Bases] RaidableBases\Difficulty_Loot\Normal --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4. 
[Raidable Bases] RaidableBases\Base_Loot\RaidBase1 --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4.
[Raidable Bases] RaidableBases\Base_Loot\RaidBase1 --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4. 
[Raidable Bases] RaidableBases\Base_Loot\RaidBase2 --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4.
[Raidable Bases] RaidableBases\Base_Loot\RaidBase2 --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4. 
[Raidable Bases] RaidableBases\Base_Loot\RaidBase3 --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4.
[Raidable Bases] RaidableBases\Base_Loot\RaidBase3 --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4. 
[Raidable Bases] RaidableBases\Base_Loot\RaidBase4 --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4.
[Raidable Bases] RaidableBases\Base_Loot\RaidBase4 --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4. 
[Raidable Bases] RaidableBases\Base_Loot\RaidBase5 --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4.
[Raidable Bases] RaidableBases\Base_Loot\RaidBase5 --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4. 
[Raidable Bases] RaidableBases\Base_Loot\RaidBase7 --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4.
[Raidable Bases] RaidableBases\Base_Loot\RaidBase7 --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4. 
[Raidable Bases] RaidableBases\Base_Loot\RaidBase9 --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4.
[Raidable Bases] RaidableBases\Base_Loot\RaidBase9 --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4. 
[Raidable Bases] RaidableBases\Base_Loot\RaidBases --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4.
[Raidable Bases] RaidableBases\Base_Loot\RaidBases --- Invalid character after parsing property name. Expected ':' but got: ". Path '[648].skin', line 3894, position 4. 

it's telling you where the error is

Path '[648].skin', line 3894, position 4. 

and what it should be changed to

Expected ':' but got: ".