Here are the steps I took to solve it in Windows 10, which I ironically could only find on a Japanese site here.
For those who don't read Japanese:
1.Press the Windows key and search for "Env" as in "Environment Variables."
2. Open the result "Edit the system environment variables."
3. This will open the System Properties dialogue; here, click the "Environment Variables..." button in the lower right-hand corner of the window.
4. In the section "User environment variables for <username>", click the "New..." button.
5. In the "New User Variable" dialogue, type MAYA_APP_DIR in the "Variable Name" field and
6. In the "Variable value" field, type in a directory path to which you have full write access.
7. Click the "OK" button in the dialogue to save your new environment variable.
8. Click the "OK" button in the Environment Variables window to save changes.
9. Restart your machine, just in case.
10. Try and launch Maya again.
This worked for me with Maya LT 2019.
Just a bit on community etiquette: might I suggest to avoid marking responses with nothing but a link as the accepted solution? The link that the provided by the Accepted Solution as of this posting no longer works.
Answering parties may also want to reconsider replying "Google it" as a suggested solution, too.