RuntimeError: the sip module implements API v11.0 to v11.2 but the PyQt5.QtCore module requires API v11.3
<p>I recently installed PyQt4 onto my system and started doing some basic tasks (course work), it worked fine. </p>

<p>Then, after some days, I was trying to work with <code>matplotlib</code>.</p>

<p>When I tried <code>import matplotlib.pyplot as plt</code>,I get the following error:</p>

<pre><code>Traceback (most recent call last):
  File "C:\Users\user\Desktop\Confusion.py", line 1, in &lt;module&gt;
    import matplotlib.pyplot as plt
  File "C:\Program Files\Anaconda3\lib\site-packages\matplotlib\pyplot.py", line 114, in &lt;module&gt;
    _backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()
  File "C:\Program Files\Anaconda3\lib\site-packages\matplotlib\backends\__init__.py", line 32, in pylab_setup
    globals(),locals(),[backend_name],0)
  File "C:\Program Files\Anaconda3\lib\site-packages\matplotlib\backends\backend_qt5agg.py", line 16, in &lt;module&gt;
    from .backend_qt5 import QtCore
  File "C:\Program Files\Anaconda3\lib\site-packages\matplotlib\backends\backend_qt5.py", line 27, in &lt;module&gt;
    import matplotlib.backends.qt_editor.figureoptions as figureoptions
  File "C:\Program Files\Anaconda3\lib\site-packages\matplotlib\backends\qt_editor\figureoptions.py", line 17, in &lt;module&gt;
    import matplotlib.backends.qt_editor.formlayout as formlayout
  File "C:\Program Files\Anaconda3\lib\site-packages\matplotlib\backends\qt_editor\formlayout.py", line 58, in &lt;module&gt;
    from matplotlib.backends.qt_compat import QtGui, QtWidgets, QtCore
  File "C:\Program Files\Anaconda3\lib\site-packages\matplotlib\backends\qt_compat.py", line 127, in &lt;module&gt;
    from PyQt5 import QtCore, QtGui, QtWidgets
RuntimeError: the sip module implements API v11.0 to v11.2 but the PyQt5.QtCore module requires API v11.3
[Finished in 1.9s]
</code></pre>

<p>I thought that the problem is with the installation of <code>PyQt4</code> while I already had <code>PyQt5</code>, but <a href="http://pyqt.sourceforge.net/Docs/PyQt5/installation.html" rel="noreferrer">this</a>website says that they can work properly together without any problem, provided the <code>sip</code> is of same version for both.</p>

<p>The problem seems to be coming from <code>sip</code>. </p>

<p>I followed the steps given here : <a href="https://stackoverflow.com/a/22896854/3564318">PyQt5 - SIP API 10 level error. API 11 required</a></p>

<ol>
<li><p>When I run <code>import sip</code> and then
<code>print(sip, sip.SIP_VERSION_STR)</code></p>

<p>I get the following:

4.16.9</p></li>
<li><p>Then when I run <code>sip -V</code> in the command prompt, I get <code>4.18</code>.</p></li>
</ol>

<p>I clearly see that there is in the <code>sip</code> module. </p>

<p>All I want to ask is, how do I solve this problem? </p>

<p><strong>I am on a Windows 8 64 bit system, using Anaconda3</strong></p>

<p>Any help is appreciated. :)</p>