Enabling external component directory fails export functionality on windows

Set external component directory property as '-Ddashbuilder.components.dir=<customDir>' and go to Dashbuilder Data Transfer

Click any of the below export functionality
1.Export All
2.Download option in custom export
3.Open button for dashbuilder runtime(if it is enabled)

all 3 cases leads to below error in UI

`Data export error. Check logs for more details.`

No error shown in server log

Getting `NoClassDefFoundError` in web console..please see attachment.