Spark creating huge errors.log file

Hi

Running Spark 2.7.1 in a Windows 2008 R2 Citrix environment.  Sometimes (seems random as the users claim they have not done unusual with Spark) spark.exe will start using 100% of its available CPU and create a huge errors.log file in %AppData%\Roaming\Spark\logs.  Spark keeps generating the log file until the disk is full and will keep going until the .exe is manually terminated.

This appears to be a bug but I doubt I've provided enough information for anyone to be able to trace its origin.  I have to delete the errors.log file to free up disk space so I do not have a sample to attach (although I could keep some next time it happens).

Any assistance appreciated.

David