Autolab won't accept some java files?

The current production version of autolab won't accept ?some? java files including the EdgeWeightedDiGraph.java file below. See screen shot. This error does not make sense to me because the system has clearly stored the file on the server side (you can view it through autolab or on the file system). There is no feedback file from tango, and further, there is no job number indicating that the job is assigned to tango. So, I suspect something is happening on the autolab side when the file is scheduled to be sent to tango. Other files, of course seem to work fine, so perhaps there is an unprintable character in the file that is causing problems? The deploy-ewdigraph.tar file contains the necessary elements to deploy the assessment in question on autolab.

Screen_Shot_2022-11-30_at_9.32.39_PM

EdgeWeightedDiGraph.java

deploy-ewdigraph.tar