That is very strange something is quarantined in eM Client. Could be just Malwarebytes thinks it is a problem but may not be at all so a eg: False Positive. Might just need to be included in the Malwarebytes whitelist.
Suggest to also contact Malwarebytes via their forum or contact page for advice.
(Malwarebytes page on MachineLearning/Anomalous.100)
I run Malwarebytes and have never had any file/folder flagged by MWB anywhere in eMC, as @cyberzork says it is strange.
You do not say the version of MWB you are using, there are configuration differences between the versions, I have Premium 4.5.14
You should contact support at MWB they are good an will help and if this is a false positive they will want to know.