You expect open to identify and reject all invalid names. It is not surprising that it is not always able to do this. A far better approach is to write a function that tests the name against the specification https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#naming-conventions, for windows file names.
Bill

In reply to Re: Why are there no errors when opening a filename that contains colons on Win10 by BillKSmith
in thread Why are there no errors when opening a filename that contains colons on Win10 by Lotus1

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