update-manager crashed with SIGSEGV in FileList()

The crash happened during the refreshing phase (sth like apt-get update) after removing a source (PPA) from 'Other Software' and clicking 'Close'. This window appeared...

--->
The information about available software is out-of-date

To install software and updates from newly added or changed sources, you have to reload the information about available software.

You need a working internet connection to continue.
<---

...and I clicked 'Reload'. The window went gray for approximately 3 seconds prior to the crash.

ProblemType: Crash
DistroRelease: Ubuntu 15.10
Package: update-manager 1:15.10.3
ProcVersionSignature: Ubuntu 4.2.0-25.30-generic 4.2.6
Uname: Linux 4.2.0-25-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 2.19.1-0ubuntu5
Architecture: amd64
CurrentDesktop: Unity
Date: Thu Jan 21 08:18:57 2016
ExecutablePath: /usr/bin/update-manager
GsettingsChanges:
 b'com.ubuntu.update-manager' b'show-details' b'true'
 b'com.ubuntu.update-manager' b'window-height' b'876'
 b'com.ubuntu.update-manager' b'first-run' b'false'
 b'com.ubuntu.update-manager' b'window-width' b'1539'
 b'com.ubuntu.update-manager' b'launch-time' b'1453360699'
InstallationDate: Installed on 2015-12-28 (23 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
InterpreterPath: /usr/bin/python3.4
PackageArchitecture: all
ProcCmdline: /usr/bin/python3 /usr/bin/update-manager
SegvAnalysis:
 Segfault happened at: 0x7f4d9ed53797: mov 0xc(%rdx),%edx
 PC (0x7f4d9ed53797) ok
 source "0xc(%rdx)" (0x69662d74736f6f6e) not located in a known VMA region (needed readable region)!
 destination "%edx" ok
SegvReason: reading unknown VMA
Signal: 11
SourcePackage: update-manager
StacktraceTop:
 ?? () from /usr/lib/python3/dist-packages/apt_pkg.cpython-34m-x86_64-linux-gnu.so
 ?? ()
 ?? ()
 PyEval_EvalFrameEx ()
 PyEval_EvalCodeEx ()
Title: update-manager crashed with SIGSEGV in PyEval_EvalFrameEx()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo