Blogger error bX-q957zg while updating Blog Posts Section

Problem Statement

When I try to edit the Blog Posts section on the blog layout page (Layout->Blog Posts Section->Edit), I get the following error:

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Describe what you were doing when you got this error.Provide the following error code and additional information.
bX-q957zg
ADDITIONAL INFORMATION
blogID: 9179404155XXXXXXXX
host: www.blogger.com
uri: /rearrange
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It prevents me from making configuration changes such as number of blog posts to display on the main page, date format, Adsense settings etc.

Root Cause

In my case, I found that the root cause was the way I had defined the font and color settings in the header of my custom template. Refer to the text in red below:

<Variable name="t2HeaderBgColor" description="Theme 2 Header Background Color" type="color" default="#885" value="#4b3c37">
<Variable name="t2HeaderColor" description="Theme 2 Header Color" type="color" default="#885" value="#FFFFFF">

<Variable name="t2SecHeaderBgColor" description="Theme 2 Sec Header Background Color" type="color" default="#885" value="#cde196">
<Variable name="t2SecHeaderColor" description="Theme 2 Secondary Header Color" type="color" default="#885" value="$t2HeaderBgColor">

I was referring to a previously defined font using $variableName syntax. Though I get the correct results with this notation, blogger apparently doesn't like it. This is the root cause of the problem.

Solution

Simply replace $variableName with the actual color code and the problem disappears !

<Variable name="t2SecHeaderColor" description="Theme 2 Secondary Header Color" type="color" default="#885" value="#4b3c37">

Note that the root cause and the solution was applicable in my case, but may not necessarily be applicable to yours. If this solution doesn't fix your problem, I suggest you look around for other similar problems in the font definition section of your template.

Good luck !