I am also having this error. My problem is after uninstalling the plugin and reinstalling it I can't even add a fork. I get a "failed to set configuration" error when I go to add a fork. Here's the details:
Code
Error #3002:
exception 'OMVException' with message 'Failed to set configuration' in /usr/share/openmediavault/engined/rpc/sickbeard.inc:453
Stack trace:
#0 [internal function]: OMVRpcServiceSickbeard->setFork(Array, Array)
#1 /usr/share/php/openmediavault/rpcservice.inc(125): call_user_func_array(Array, Array)
#2 /usr/share/php/openmediavault/rpc.inc(79): OMVRpcServiceAbstract->callMethod('setFork', Array, Array)
#3 /usr/sbin/omv-engined(500): OMVRpc::exec('Sickbeard', 'setFork', Array, Array, 1)
#4 {main}