no such algorithm: SHA1withRSA for provider BC

(this is in KAPK not KWGT but I can't choose it in the form)
I'm trying to generate an APK from a KWGT widget, when I hit Build I get this error

"no such algorithm: SHA1withRSA for provider BC"

after "Starting up..."

When I hit Export I get the same error after "Creating zip file; Storing keystore password"

I was looking all over and couldn't find documentation for KAPK so maybe my whole workflow is completely off and I don't know. I'm trying to make the widget standalone.


I have this same issue and literally cannot find any documentation anywhere on wtf it means