I can't tell at which point in your code these errors are coming from.
The error messages indicate that there is a ToExpression wrapped around a string. Here is an input that gives the same error:
In[6]:= ToExpression["\U"]
During evaluation of In[6]:= Syntax::stresc: Unknown string escape \U.
Out[6]= $Failed
So perhaps this is in your -run "Get[ path to file]" code??? On windows machines, you have to be very careful with the path names because "\" is an escape character in Mathematica. A safer way to specify the path is to use FilenameJoin, e.g.,
In[7]:= FileNameJoin[{"Users","chadk","temp","demo.m"}]
Out[7]= Users\chadk\temp\demo.m
Then your command line input would look something like this:
C:\Users\chadk> "\Program Files\Wolfram Research\Mathematica\11.1\WolframKernel.exe" -run "Get[FileNameJoin[{\"Users\",\"chadk\",\"temp\",\"demo.m\"}]]" n
where the escape character (/) is used for the strings inside the FileName