Error 1: An Input Parameter Is Invalid in LabVIEW

Issue Details

• When running my LabVIEW program, I get an error message when trying to open, write/read or close certain files such as images, text files, etc:

• I'm getting error Error 1 in LabVIEW when trying to manipulate a file, I can see the file name including the characters ":\" in the error message, why is that being included in the name?

Solution

• The Windows file naming convention prohibits the use of certain characters in the file path that is eventually input to the File I/O sub VI's. This error is most commonly associated with backslash, colon, and other control characters that are unintentionally included when a string is converted to a file path - especially if a date is included in that string (i.e. 9/22/04). The following characters should not be present in any file name: \ / : * ? " < > | . Removing or replacing all of the control characters from the input string should remedy this error.
  • If you are using string values and converting them to paths, avoid adding carriage returns or line feeds. For example, if the Enter key was pressed when typing the string, it adds a line feed, which contains an invalid character for a file name. 
• If you are using the Build Path function do not leave the base path terminal empty if you are only going to specify the file name. For example, if you leave the base path terminal of the function empty and enter "File.txt" in the name or relative path terminal, the output value will be "File.txt:\".
• This error could also occur if you specify a file name without a drive path inside a file path entry. You need to make sure that your drive path is included along with your file name (i.e. C:\filename or E:\filename).
• An invalid input path can be a result of LabVIEW not having proper access to the target file. Check the File or Folder Permissions, try to Log in as Administrator, or ask your IT department about Group Policies on the specified destination
• This error could also occur if you specify a path whose length exceeds the maximum permitted path length in LabVIEW which varies according to the version of Windows that you are using.

Additional Information

Even if control characters are not visible in the input string they may still be present, but are easy to find. Connect either a control or indicator to the input string and enable backslash code display (select Properties » Display style by right-clicking the indicator). If you determine that control characters have been included, they can be replaced with a non-control character (such as underscore) by using the Search and Replace Pattern .vi located on the string sub-palette. See snippet below for example on how to apply this VI to alleviate issues that cause Input Parameter Invalid errors.
 

 Note: This image is a LabVIEW snippet, which includes LabVIEW code that you can reuse in your project. To use a snippet, right-click the image, save it to your computer, and drag the file onto your LabVIEW diagram.