Steve the creeper

Hi I am trying to do is make the Steve walk a distance stop then walk a pretty short way and stop and all of the this is done using the button that says create a walking animation to next key frame. The problem is when I click create a walking animation to next key frame ( this is to make the animation after stopping the first time) it gives me this error 6:41:53 PM version: 1.0.2 (official 2)
6:41:53 PM gm_version: 1.4.1514
6:41:53 PM build date: 11/7/2015 10:55:33 AM
6:41:53 PM YYC: yes
6:41:53 PM OS: Windows_NT
6:41:53 PM USERDOMAIN: ninja-drummer
6:41:53 PM USERNAME: Nolan
6:41:53 PM USERPROFILE: C:\Users\Nolan
6:41:53 PM APPDATA: C:\Users\Nolan\AppData\Roaming
6:41:53 PM video_adapter_0_name: NVIDIA GeForce GTX 970
6:41:53 PM video_adapter_0_driver_version_high: 655378
6:41:53 PM video_adapter_0_device_name: \\.\DISPLAY1
6:41:53 PM video_adapter_0_driver_version_low: 857868
6:41:53 PM os_version: 393217
6:41:53 PM os_is_network_connected: yes
6:41:53 PM os_get_language: en
6:41:53 PM os_get_region: US
6:41:53 PM working_directory: C:\Mine-imator\
6:41:53 PM file_directory: C:\Users\Nolan\AppData\Roaming\Mine_imator\
6:41:53 PM Old log found
6:41:53 PM DLL init
6:41:53 PM file.dll
6:41:53 PM gzunzip.dll
6:41:53 PM movie.dll
6:41:53 PM Movie init
6:41:53 PM window.dll
6:41:53 PM texture.dll
6:41:53 PM Texture init
6:41:55 PM exe_directory: C:\Mine-imator\
6:41:55 PM Trying to save files
6:41:55 PM Files saved
6:41:55 PM Shader init
6:41:55 PM shaders_are_supported: yes
6:41:55 PM shader_high_ssao_blur compiled: yes
6:41:55 PM shader_high_ssao compiled: yes
6:41:55 PM shader_high_ssao_depth_normal compiled: yes
6:41:55 PM shader_high_light_apply compiled: yes
6:41:55 PM shader_high_light_night compiled: yes
6:41:55 PM shader_high_light_point compiled: yes
6:41:55 PM shader_high_light_spot compiled: yes
6:41:55 PM shader_high_light_sun compiled: yes
6:41:55 PM shader_high_fog_apply compiled: yes
6:41:55 PM shader_high_fog compiled: yes
6:41:55 PM shader_high_dof compiled: yes
6:41:55 PM shader_high_aa compiled: yes
6:41:55 PM shader_replace compiled: yes
6:41:55 PM shader_draw_texture compiled: yes
6:41:55 PM shader_depth compiled: yes
6:41:55 PM shader_color_fog_lights compiled: yes
6:41:55 PM shader_color_fog compiled: yes
6:41:55 PM shader_blend_fog compiled: yes
6:41:55 PM shader_blend compiled: yes
6:41:55 PM shader_border compiled: yes
6:41:55 PM Create vertex format
6:41:55 PM Render init
6:41:55 PM Ground model init
6:41:55 PM Character models init
6:41:55 PM Windows init
6:41:55 PM Lists init
6:41:55 PM Load language file: C:\Mine-imator\Other\Languages\english.txt
6:41:55 PM Make transitions
6:41:55 PM Globals init
6:41:55 PM Opening pack from folder: C:\Mine-imator\Other\Textures\
6:41:55 PM Loading settings: C:\Mine-imator\Other\settings.file
6:41:55 PM load_format: 2
6:41:55 PM Loading recent: C:\Mine-imator\Other\recent.file
6:41:55 PM Loading closed alerts: C:\Mine-imator\Other\alerts.file
6:41:55 PM Startup OK
6:41:55 PM Resetting project
6:41:55 PM Destroying instances
6:41:55 PM Project resetted
6:41:55 PM Show popup: startup
6:41:58 PM Opening project: C:\Mine-imator\Projects\kill the creeper 2\kill the creeper 2.mproj
6:41:58 PM load_folder: C:\Mine-imator\Projects\kill the creeper 2
6:41:58 PM load_format: 10
6:41:58 PM Resetting project
6:41:58 PM Destroying instances
6:41:58 PM Project resetted
6:41:58 PM save_folder: C:\Mine-imator\Projects\kill the creeper 2
6:41:58 PM Templates: 63
6:41:58 PM Timelines: 98
6:41:58 PM Resources: 3
6:41:58 PM Get template iids
6:41:58 PM Get particle type iids
6:41:58 PM Get keyframe iids
6:41:58 PM Get timeline iids
6:41:58 PM Update program
6:41:58 PM Project loaded
6:41:58 PM Loading schematic: C:\Mine-imator\Projects\kill the creeper 2\Creek.schematic
6:41:59 PM Loading schematic: C:\Mine-imator\Projects\kill the creeper 2\Hilly field.schematic
6:42:01 PM Loading schematic: C:\Mine-imator\Projects\kill the creeper 2\Oak tree1.schematic
6:48:20 PM Action: action_tl_select
6:48:25 PM Action: action_tl_select
6:48:25 PM Action: action_tl_keyframe_create
6:48:26 PM Action: action_tl_select
6:48:27 PM Action: action_tl_keyframe_select
6:48:27 PM Action: action_tl_keyframes_move_done
6:48:32 PM Action: action_tl_keyframes_remove
6:48:38 PM Action: action_tl_select
6:48:48 PM Action: action_tl_select
6:49:01 PM Action: action_tl_keyframe_select
6:49:01 PM Action: action_tl_keyframes_move_done
6:49:04 PM Action: action_tl_import_loop
please help. thanks