I've also found a few things that help on an android tablet on the mobile wgt game.
1. Shut the wgt mobile app DOWN/OFF.
2. Go to Settings; Go to App Settings; Go to the wgt App;
Clear the wgt App Cache; then Do a Force Stop;
Back out of the wgt App to Settings; and go to the Google item in the Account group;
Open the Google item, Select the Ads item in Services;
Select the "Reset advertising ID" item, Select "OK" , replacing your advertising ID
Close SETTINGS window, Open wgt App, SELECT "Free Credits" on wgt app main page.
This has allowed me to continue to view videos & get the credits.
I agree with the comment abofe about the reset time being 7pm UTC which for me is 12 noon MST , sometimes it sems to be about 10 or 15 minutes late...??? who knows ?
Works for me. Been getting the allotted 150 credits regularly.
Someone said the vid "system" was down later this afternoon, I don't know?