Elasticsearch wont start - ShardNotFoundException

Elastic Stack Elasticsearch
1

my elasticsearch server was improperly shutdown.
Upon restart elasticsearch service wont start.
Apparently this is because of an shard problem.
My question is how do i solve this?
should i delete the indice "tor"?
or is there a turn around?
I tried to reassign the shard with no success.
Here's the log entry where i think the problem resides.

RemoteTransportException[[Anais][xxx.xxx.xxx.xxx:9300]
[indices:data/read/search[phase/query]]]; 
nested: ShardNotFoundException[no such shard];
Caused by: [tor][[tor][4]] ShardNotFoundException[no such shard]
2

I can't figure it out how, but the problem is solved.
maybe elastic search was executing some kind of slow operation making it unavailable...
if this makes any sense a appretiate a comment.