[TYPO3-Solr] Index Queue Worker error after upgrade to 2.1.0

[Jan Slusarczyk]

> could you please try to truncate the Index Queue and the initialize it
> again? That should solve it...

I have truncated table tx_solr_indexqueue_item and ran Initialize Index 
Queue in Search module of BE. But the error in scheduler is still the 
same. It didn't even start - every (of 4) worker is stuck on 0%...

Regards
Jan