Fixing an error in Python "ValueError: could not convert string to float: '#VALUE!'"

I have different columns of data in a file and this commands works for some columns but gives these errors for the rest of them, can anybody help me understand what the problem is please?

Data4 = df4['lab 4']

plt.plot(Data4 , label = "line")

Data4.describe()

    ---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-55-df75dc88ca04> in <module>()
      1 col4 = df4['col 4']
      2 
----> 3 plt.plot(col4, label = "line")
      4 
      5 col4.describe()

6 frames
/usr/local/lib/python3.7/dist-packages/matplotlib/pyplot.py in plot(scalex, scaley, data, *args, **kwargs)
   2761     return gca().plot(
   2762         *args, scalex=scalex, scaley=scaley, **({"data": data} if data
-> 2763         is not None else {}), **kwargs)
   2764 
   2765 

/usr/local/lib/python3.7/dist-packages/matplotlib/axes/_axes.py in plot(self, scalex, scaley, data, *args, **kwargs)
   1647         lines = [*self._get_lines(*args, data=data, **kwargs)]
   1648         for line in lines:
-> 1649             self.add_line(line)
   1650         self._request_autoscale_view(scalex=scalex, scaley=scaley)
   1651         return lines

/usr/local/lib/python3.7/dist-packages/matplotlib/axes/_base.py in add_line(self, line)
   1848             line.set_clip_path(self.patch)
   1849 
-> 1850         self._update_line_limits(line)
   1851         if not line.get_label():
   1852             line.set_label('_line%d' % len(self.lines))

/usr/local/lib/python3.7/dist-packages/matplotlib/axes/_base.py in _update_line_limits(self, line)
   1870         Figures out the data limit of the given line, updating self.dataLim.
   1871         """
-> 1872         path = line.get_path()
   1873         if path.vertices.size == 0:
   1874             return

/usr/local/lib/python3.7/dist-packages/matplotlib/lines.py in get_path(self)
   1025         """
   1026         if self._invalidy or self._invalidx:
-> 1027             self.recache()
   1028         return self._path
   1029 

/usr/local/lib/python3.7/dist-packages/matplotlib/lines.py in recache(self, always)
    673         if always or self._invalidy:
    674             yconv = self.convert_yunits(self._yorig)
--> 675             y = _to_unmasked_float_array(yconv).ravel()
    676         else:
    677             y = self._y

/usr/local/lib/python3.7/dist-packages/matplotlib/cbook/__init__.py in _to_unmasked_float_array(x)
   1315         return np.ma.asarray(x, float).filled(np.nan)
   1316     else:
-> 1317         return np.asarray(x, float)
   1318 
   1319 

ValueError: could not convert string to float: '#VALUE!'