Error occur when loading resource after minimized on android

Help~
on android mobile, I put the program to the background, and then I put it to the main screen.
the new loading resource like texture occurs error.
What should I do?

I have the same issue but I am not sure how to fix it. I am getting Failed to lock index buffer after restoring from background. I have created ticket which is similar: https://github.com/urho3d/Urho3D/issues/1684 . It looks like threading issue.