Plotter is not working

[FoamyGuy]

Attempting to access the Serial plotter results in the page getting stuck and this error in the JS console:

index.js:112 Uncaught (in promise) ReferenceError: textValues is not defined
    at OR (index.js:112:88)
    at FR.writeToTerminal (index.js:112:4686)
    at YE._writeToTerminal (index.js:93:1631)
    at YE._processToken (index.js:93:5408)
    at YE._processQueuedTokens (index.js:93:5088)
    at YE.onSerialReceive (index.js:93:6031)
    at FR.onSerialReceive (index.js:112:4192)
    at FR._readSerialLoop (index.js:118:589)