Data Export Extension Fails on Import (Validation Not Acceptable) TW 8.2
That seems to be a known issue due to a JAR conflict since at least ThingWorx 7.4.
There was a thread already in the community for that, please have a look:
As mentioned in the Marketplace and also in the thread above, the extension is not supported and it is delivered in "as-is" condition.
I hope that helps!