The bug has been opened https://bugs.launchpad.net/bugs/402221
"This error is triggered when there mp3 file and text file with exact same file name.

1) mkdir /tmp/t
2) cp somesong.mp3 /tmp/t/t.mp3
3) echo 'foo' > /tmp/t/t.txt
4) totem /tmp/t/t.mp3

(totem:4027): GLib-GObject-WARNING **: IA__g_object_set_valist: object class `GstPlayBin2' has no property named `queue-size'

(totem:4027): GLib-GObject-WARNING **: IA__g_object_set_valist: object class `GstPlayBin2' has no property named `queue-threshold'
0:00:27.848563598 4027 0x96fd5e0 ERROR totem bacon-video-widget-gst-0.10.c:348:bvw_error_msg: message = This appears to be a text file
0:00:27.848635953 4027 0x96fd5e0 ERROR totem bacon-video-widget-gst-0.10.c:350:bvw_error_msg: domain = 3118 (gst-stream-error-quark)
0:00:27.848657534 4027 0x96fd5e0 ERROR totem bacon-video-widget-gst-0.10.c:351:bvw_error_msg: code = 5
0:00:27.848670525 4027 0x96fd5e0 ERROR totem bacon-video-widget-gst-0.10.c:352:bvw_error_msg: debug = gstdecodebin2.c(1511): type_found (): /GstPlayBin2:play/GstURIDecodeBin:uridecodebin1/GstDecodeBin2:decodebin20:
decodebin2 cannot decode plain text files
0:00:27.848686588 4027 0x96fd5e0 ERROR totem bacon-video-widget-gst-0.10.c:353:bvw_error_msg: source = <decodebin20>
0:00:27.848723744 4027 0x96fd5e0 ERROR totem bacon-video-widget-gst-0.10.c:354:bvw_error_msg: uri = file:///tmp/t/t.mp3
** Message: Error: This appears to be a text file
gstdecodebin2.c(1511): type_found (): /GstPlayBin2:play/GstURIDecodeBin:uridecodebin1/GstDecodeBin2:decodebin20:
decodebin2 cannot decode plain text files

0:00:32.137128269 4027 0x96fd5e0 ERROR totem bacon-video-widget-gst-0.10.c:348:bvw_error_msg: message = This appears to be a text file
0:00:32.137399463 4027 0x96fd5e0 ERROR totem bacon-video-widget-gst-0.10.c:350:bvw_error_msg: domain = 3118 (gst-stream-error-quark)
0:00:32.137629520 4027 0x96fd5e0 ERROR totem bacon-video-widget-gst-0.10.c:351:bvw_error_msg: code = 5
0:00:32.137816346 4027 0x96fd5e0 ERROR totem bacon-video-widget-gst-0.10.c:352:bvw_error_msg: debug = gstdecodebin2.c(1511): type_found (): /GstPlayBin2:play/GstURIDecodeBin:uridecodebin1/GstDecodeBin2:decodebin22:
decodebin2 cannot decode plain text files
0:00:32.138153400 4027 0x96fd5e0 ERROR totem bacon-video-widget-gst-0.10.c:353:bvw_error_msg: source = <decodebin22>
0:00:32.138352028 4027 0x96fd5e0 ERROR totem bacon-video-widget-gst-0.10.c:354:bvw_error_msg: uri = file:///tmp/t/t.mp3
** Message: Error: This appears to be a text file
gstdecodebin2.c(1511): type_found (): /GstPlayBin2:play/GstURIDecodeBin:uridecodebin1/GstDecodeBin2:decodebin22:
decodebin2 cannot decode plain text files

totem 2.27.1-1ubuntu5"