Decrediton 2.0.6 doesn't send

Sending transaction from default wallet stays pending indefinitely.
The transaction has been pending for more than 4 days after its creation.
Clicking on the transaction, "dcrdata.decred.org" tell me that  - No matching page, block, address or transaction that could be found.
that transaction has not been recorded.
Could it be that some configuration has changed in the wallet?
Thanks.