Fatal error when uploading a 'Progress File'

[JamesBisese]

Describe the bug

When a user loads a Progress file and then changes tabs to 'Filter' a fatal error occurs "Input object must be of class 'data.frame'"

To Reproduce

Steps to reproduce the behavior:

1. Load excel data file ()
tada_output_utah_10rows.xlsx
, then download 'Working Dataset' zip file.

2. Uncompress zip file on local disk

3. Open TADAShiny and go to the Load tab panel. Scroll down to the " Optional: Upload Progress File" section of the panel

4. Load the progress file (the .RData file that was in the zip file)

5. In TADAShiny, click the tab '4. Filter'

6. See error
In the users browser the screen is grey and the app is unresponsive (the error condition when the app stops)

In the RStudio console there is this error

Error: (converted from warning) Error in TADA_CheckType: Input object must be of class 'data.frame'

Please include your Water Quality Portal data query inputs from the Load
data tab:

The error is occurring because the argument being tested is not a 'data.frame'

library(EPATADA)
file: Utilies.R

TADA_CheckType <- function(arg, type, paramName) {
  if ((type %in% class(arg)) == FALSE) {
    # if optional parameter name not specified use arg in errorMessage
    if (missing(paramName)) {
      paramName <- arg
    }
    errorMessage <- paste(paramName, " must be of class '", type, "'", sep = "")
    return(stop(errorMessage))
  }
}

Debugging (by inserting a browser() statement in the function above and then running 
document("C:/Data_and_Tools/tada/working/app/canonical/EPATADA"))

Called from: TADA_CheckType(.data, "data.frame", "Input object")
Browse[1]> typeof(arg)
[1] "list"

Expected behavior

A clear and concise description of what you expected to happen.

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Additional context

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Reminders for TADA contributors addressing this issue

Bug fixes should include the following work:

• Create or edit the code.

• Document all code using line/inline and/or multi-line/block comments
  to describe what is does.

• Create or edit tests in tests/testthat folder to help prevent and/or
  troubleshoot potential future issues.

• If your code edits impact other functionality in the shiny
  app, ensure those are updated as well.

• Run styler::style_pkg(), devtools::document(), and devtools::check()
  and address any new notes or issues before creating a pull request.

[JamesBisese]

Now I'm not so sure I understand the error condition. I got it to work correctly using the Utak 15k record example data. (Which must be loading from a .RData file or similar in the backend).
I need to rework the test case. It probably has something to do with the 'Excel' uploads rather that the way the .RData file is generated. Something isn't the same in the way they are processed.