This is a known issue with the region-free GamePad plugin (found at
wiiu/environments/aroma/plugins/drc_region_free.wps
) on your Wii U SD card, which is included as part of the base Aroma. This plugin allows you to pair GamePads from outside of your region, since they are otherwise region-locked. However, it causes this issue if the Wii U is powered on while the GamePad is not connected.
Even if you do need this feature, you only need it for the actual pairing, once that is completed you no longer need to run the plugin; paired out-of-region GamePads will remain paired.
If you don't need this feature (any more), you can remove or disable that plugin to avoid the issue. You can do this by either deleting the
drc_region_free.wps
file, or renaming it to no longer be picked up by the plugin loader. Here's some examples of filenames that will
not be loaded as plugins:
.drc_region_free.wps
(period at start)
_drc_region_free.wps
(underscore at start)
drc_region_free.wps.off
(file extension is not .wps
)