My cloud app stopped working after update to android 10

Firmware 2.12.127 is not used on a second generation single bay My Cloud. Instead that firmware appears to be used on the multi bay My Cloud models. What specific My Cloud unit do you have?

The single bay My Cloud models (first and second gen) look like this:

As a general notice to anyone reading this thread, Do not try to use the firmware links in the WD My Cloud v3.x, v4.x and v2.x Firmware Versions Download Links page on a multi bay My Cloud Model. The firmware in the WD My Cloud v3.x, v4.x and v2.x Firmware Versions Download Links page is solely for the single bay/single drive My Cloud versions.