[] comes under valid characters, so it is an issue with dbfs.fs.
dbutils.fs.ls("/Workspace/Users/user@databricks.com/qwe[rt]") fails with java.net.URISyntaxException: Illegal character in path at index
I tested a workaround meanwhile that can help you read the file.
%python
path = "file:/Workspace/Users/user@databricks.com/qwe\\[rt\\]/hello"
df = spark.read.text(path)
display(df)
For the Dbfs bug, I see we have an internal tracking ticket SC-163860.
Thanks!
