I have very much came to depend on Firefox. I've tried everything mentioned to users with same problem. Even Passwords and Settings have white windows (no text or anything else showing. When I reinstall Firefox I get vcruntime140_1.dll error. How can I fix it? I have the latest update. While writing this I went back to double check the vcruntime140_1.dll install. I found it wasn't on the main Mozilla Directory - so I copied it. And now Firefox works! The file came from https://www.dll-files.com/. I don't need any further assistance. Just leaving this as a record for others who may be having a hard time. Thanks Mozilla for all you do!