I am using Workrave 1.10.1-4 on Linux Mint 17 (Ubuntu 14.04) and workrave now always quits at startup. I already clear the settings (removed .workrave), but with no results. Unfortunately I can't give more informations than below, as the debugging symbols are not available in the repos.

$ workrave
*** Error in `workrave': malloc(): memory corruption: 0x0000000002463c40 ***
Aborted

Or in gdb:

$ gdb workrave
GNU gdb (Ubuntu 7.7.1-0ubuntu5~14.04.2) 7.7.1
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from workrave...(no debugging symbols found)...done.
(gdb) r
Starting program: /usr/bin/workrave 
Traceback (most recent call last):
  File "/usr/share/gdb/auto-load/usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.19-gdb.py", line 63, in <module>
    from libstdcxx.v6.printers import register_libstdcxx_printers
ImportError: No module named 'libstdcxx'
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7fffebd72700 (LWP 24265)]
[New Thread 0x7fffeb364700 (LWP 24266)]
[New Thread 0x7fffeab63700 (LWP 24267)]
[New Thread 0x7fffea15d700 (LWP 24268)]
*** Error in `/usr/bin/workrave': free(): invalid next size (normal): 0x0000000000c59570 ***

Program received signal SIGABRT, Aborted.
0x00007ffff2f3bcc9 in raise () from /lib/x86_64-linux-gnu/libc.so.6
(gdb)

Or:

$ gdb workrave
GNU gdb (Ubuntu 7.7.1-0ubuntu5~14.04.2) 7.7.1
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from workrave...(no debugging symbols found)...done.
(gdb) r
Starting program: /usr/bin/workrave 
Traceback (most recent call last):
  File "/usr/share/gdb/auto-load/usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.19-gdb.py", line 63, in <module>
    from libstdcxx.v6.printers import register_libstdcxx_printers
ImportError: No module named 'libstdcxx'
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7fffebd72700 (LWP 25019)]
[New Thread 0x7fffeb364700 (LWP 25020)]
[New Thread 0x7fffeab63700 (LWP 25021)]
[New Thread 0x7fffea15d700 (LWP 25022)]
*** Error in `/usr/bin/workrave': malloc(): smallbin double linked list corrupted: 0x0000000000c410f0 ***

Program received signal SIGABRT, Aborted.
0x00007ffff2f3bcc9 in raise () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) r