Multiple errors with assets

[githubfan1]

Lately I have seen a lot of errors in the log file 'augustus-log.txt' such as:

ERROR: Unable to open png file Cursors/Color_Cursors.png
INFO: Loading assetlist file admin_logistics.xml
INFO: Loading assetlist file aesthetics.xml
INFO: Loading assetlist file health_culture.xml
INFO: Unable to open png file Cursors/Color_Cursors.png (message repeats 2 times)
INFO: Loading assetlist file Industry.xml
INFO: Loading assetlist file military.xml
INFO: Loading assetlist file monuments.xml
ERROR: Unable to find image on current group with id Construction_Part_TimberPad_Shadow
INFO: Invalid layer for image City_Mint_Construction_01
INFO: Unable to find image on current group with id Construction_Part_TimberPad_Shadow (message repeats 1 time)
INFO: Invalid layer for image Lighthouse_Construction_01
INFO: Loading assetlist file terrain_maps.xml
INFO: Loading assetlist file ui.xml
ERROR: Unable to open png file Graphics/UI/Mothball_1.png
INFO: Unable to load image Mothball_1
ERROR: Unable to open png file Graphics/UI/Mothball_2.png
INFO: Unable to load image Mothball_2
ERROR: Unable to open png file Graphics/UI/Mothball_3.png
INFO: Unable to load image Mothball_3
ERROR: Unable to open png file Graphics/UI/Mothball_4.png
INFO: Unable to load image Mothball_4
INFO: Loading assetlist file walkers.xml
ERROR: Unable to open png file Graphics/Walkers/caravanserai_walker_death_06.png
INFO: Unable to load image caravanserai_walker_death_06
INFO: Invalid layer for image caravanserai_walker_death_06
ERROR: Unable to open png file Graphics/Walkers/caravanserai_walker_death_07.png
INFO: Unable to load image caravanserai_walker_death_07
INFO: Invalid layer for image caravanserai_walker_death_07
ERROR: Unable to open png file Graphics/Walkers/caravanserai_walker_death_08.png
INFO: Unable to load image caravanserai_walker_death_08
INFO: Invalid layer for image caravanserai_walker_death_08
ERROR: Unable to open png file Graphics/Walkers/overseer_death_05.png
INFO: Unable to load image overseer_death_05
INFO: Invalid layer for image overseer_death_05
ERROR: Unable to open png file Graphics/Walkers/caravanserai_overseer_death_05.png
INFO: Unable to load image caravanserai_overseer_death_05
INFO: Invalid layer for image caravanserai_overseer_death_05
INFO: Loading assetlist file warriors.xml
ERROR: Unable to find image on current group with id catapult_fr_n_06_rock
INFO: Invalid layer for image catapult_fr_nw_06
ERROR: Unable to find image on current group with id catapult_fr_n_07_rock
INFO: Invalid layer for image catapult_fr_nw_07
INFO: Creating atlas texture with size 2845x2845
INFO: Creating atlas texture with size 3245x3245
INFO: Creating atlas texture with size 756x756
INFO: Model loaded
INFO: Asset image not found: Garden_Gate