: in my attempt to migrate for m 3.6.x to 4.3.0 I stumbled upon an issue loading : the MySQL driver from the [instance]/lib dir: : : Caused by: java.lang.ClassNotFoundException: : org.apache.solr.handler.dataimport.DataImportHandler
one of us is mistaken by what that error means. you say it means that the MySQL driver isn't being loaded, but nothing in your mail suggests to me that there is a problem loading hte MySql driver. what i see is that Solr can't seem to load the DIH class, suggesting that the dataimporthandler jar is not getting loaded. There may or nay not also be a problem loading the MySQL driver, but nothing is even going to attempt to do so unless Solr can successfully construct an instance of the DataImportHandler. So unless there are more details to your error that start mentioning the MySql classes, i would check your lib settings for loading the DIH jars and make sure those are right. -Hoss
