ERROR: from element /GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0: Internal data stream error

Running on Ubuntu 18.04LTS

Have installed the v4l2loopback package and loaded the module. The virtual device appears as /dev/video5

I attempt to use v4l2loopback-ctl to set the caps:

v4l2loopback-ctl set-caps "video/x-raw,format=UYVY, width=640, height=480" /dev/video5

Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
0:00:00.012052448 9986 0x55637bab2f70 WARN basesrc gstbasesrc.c:3055:gst_base_src_loop:<videotestsrc0> error: Internal data stream error.
0:00:00.012064227 9986 0x55637bab2f70 WARN basesrc gstbasesrc.c:3055:gst_base_src_loop:<videotestsrc0> error: streaming stopped, reason not-negotiated (-4)
ERROR: from element /GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0: Internal data stream error.
Additional debug info:
gstbasesrc.c(3055): gst_base_src_loop (): /GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0:
streaming stopped, reason not-negotiated (-4)
ERROR: pipeline doesn't want to preroll.
Setting pipeline to NULL ...
Freeing pipeline ...
output to /dev/video5 failed

In addition, I try and test the virtual device using the following command:

gst-launch-1.0 -v v4l2src device=/dev/video5 ! fakesink

Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Setting pipeline to PLAYING ...
0:00:00.013335959 10118 0x555ee587ee30 WARN basesrc gstbasesrc.c:3055:gst_base_src_loop:<v4l2src0> error: Internal data stream error.
0:00:00.013361241 10118 0x555ee587ee30 WARN basesrc gstbasesrc.c:3055:gst_base_src_loop:<v4l2src0> error: streaming stopped, reason not-negotiated (-4)
New clock: GstSystemClock
ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Internal data stream error.
Additional debug info:
gstbasesrc.c(3055): gst_base_src_loop (): /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
streaming stopped, reason not-negotiated (-4)
Execution ended after 0:00:00.000044023
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
Setting pipeline to NULL ...
Freeing pipeline ...

Finally, I try and pipe my webcam to the virtual device using the following command:

gst-launch-1.0 v4l2src device=/dev/video3 ! video/x-raw,format=YUY2,width=640,height=480 ! v4l2sink device=/dev/video5

Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
0:00:00.082811522 10388 0x561d32c92680 WARN basesrc gstbasesrc.c:3055:gst_base_src_loop:<v4l2src0> error: Internal data stream error.
0:00:00.082833186 10388 0x561d32c92680 WARN basesrc gstbasesrc.c:3055:gst_base_src_loop:<v4l2src0> error: streaming stopped, reason not-negotiated (-4)
ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Internal data stream error.
Additional debug info:
gstbasesrc.c(3055): gst_base_src_loop (): /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
streaming stopped, reason not-negotiated (-4)
Execution ended after 0:00:00.000389218
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
Setting pipeline to NULL ...
Freeing pipeline ...

I'm guessing there is something I've either not set correctly or there is a bug in this package. I've run with a higher debug level and I get the following:

0:00:00.090301723 10454 0x556e6bd34280 INFO v4l2 gstv4l2object.c:1196:gst_v4l2_object_fill_format_list:<v4l2sink0:sink> got 0 format(s):
0:00:00.090307845 10454 0x556e6bd34280 INFO v4l2 gstv4l2object.c:4136:gst_v4l2_object_probe_caps:<v4l2sink0:sink> probed caps: EMPTY
0:00:00.090319527 10454 0x556e6bd34280 WARN basesrc gstbasesrc.c:3055:gst_base_src_loop:<v4l2src0> error: Internal data stream error.
0:00:00.090324467 10454 0x556e6bd34280 WARN basesrc gstbasesrc.c:3055:gst_base_src_loop:<v4l2src0> error: streaming stopped, reason not-negotiated (-4)
0:00:00.090335684 10454 0x556e6bd34280 INFO GST_ERROR_SYSTEM gstelement.c:2145:gst_element_message_full_with_details:<v4l2src0> posting message: Internal data stream error.
0:00:00.090354457 10454 0x556e6bd34280 INFO GST_ERROR_SYSTEM gstelement.c:2172:gst_element_message_full_with_details:<v4l2src0> posted error message: Internal data stream error.
ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Internal data stream error.