Hi,

I've upgraded from 2.9 to 3.1.1 and now I'm having some serious problems when making chanches.

Resulting in:

You don't have permission to access /course/modedit.php on this server.  Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request.

changed the rights off modedit.php from 644 to 755. No result

I found out that the existing code in a label caused the problem.

But I can't figure out whats wrong:

<p class="western"><img src="data:image/png;base64,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" name="Afbeelding9" style="font-size: 10pt; line-height: 1.5em;" height="83" width="214" align="left" border="0"></p>
<p class="western"><br clear="left">$U=U_{1}=U_{2}=U_{3}=U_{...}$<span face="Arial, sans-serif" style="font-family: Arial, sans-serif;"><span>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; (V)</span></span></p>
<p class="western"><img src="data:image/png;base64,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" name="Object11" style="vertical-align: middle;" height="21" width="130" align="absmiddle">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span face="Arial, sans-serif" style="font-family: Arial, sans-serif;"><span>(A)</span></span></p>
<p class="western"><img src="data:image/png;base64,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" name="Object125" style="vertical-align: middle;" height="61" width="144"><span face="Arial, sans-serif" style="font-family: Arial, sans-serif;">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;</span><span face="Arial, sans-serif" style="font-family: Arial, sans-serif;">(Ω)</span></p>
<p class="western"><img src="data:image/png;base64,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" name="Object12" style="vertical-align: middle;" height="41" width="146" align="absmiddle">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span face="Arial, sans-serif" style="font-family: Arial, sans-serif;"><span>(S of Ω</span></span>^{<span face="Arial, sans-serif" style="font-family: Arial, sans-serif;"><span>-1</span></span>}<span face="Arial, sans-serif" style="font-family: Arial, sans-serif;"><span>)</span></span></p>
<table style="width: 241px; height: 102px;" border="0">
<tbody>
<tr>
<td>Grootheid</td>
<td>symbool</td>
<td>Eenheid</td>
<td>symbool</td>
</tr>
<tr>
<td>spanning</td>
<td>U</td>
<td>Volt</td>
<td>V</td>
</tr>
<tr>
<td>stroom</td>
<td>I</td>
<td>Ampère</td>
<td>A</td>
</tr>
<tr>
<td>weerstand</td>
<td>R</td>
<td>Ohm</td>
<td><span>Ω</span></td>
</tr>
<tr>
<td>geleidbaarheid</td>
<td>G</td>
<td>Siemens</td>
<td><span>S of&nbsp;<span>Ω^-1</span></span></td>
</tr>
</tbody>
</table>

Any suggestion?

The problem with:

You don't have permission to access /course/modedit.php on this server.  Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request.

is happening quite often and not only with the modedit.php

Thanks.

Hans.