I have a bunch of those in the log, and it looks like they are either the cause or a symptom of the referenced files not being present. One other thing I know for sure that is an issue is the paths being passed to _Aslains_movetree_res_mods.bat being incorrect causing some files not to be copied into res_mods/<version>/gui (and probably other locations), which may be related to this problem. This was discussed in another thread but there was no resolution at that time. Right now I have to download the zip file as well and manually copy the GUI directory from there in order to get contour icons.
This is the thread previously discussing missing files: https://aslain.com/index.php?/topic/16469-calling-all-linux-users/