Can't use direct plot

 hi,there

I can not use direct plot->main form after my tran analysis finished.

Now,when I invoke the ADE from Virtuoso,and load the state of the from the session, a Message Window jumps out and shows the message below:

  - Warning -
<COM.cadence.awd.graph.GraphManager@10bbd42>
 Error attempting to load data forGraphObject={title=*, cursorPos=null, ID=trc:23449824.67}ing to load data forGraphObject={title=*, cursorPos=null, ID=trc:662907.14}

Then after my tran analysis finished,the output which I set before can plot normally as usual,but when I use direct plot->main form and click one wire of my schematic,there is an message like below in the CIW:

\o *Error*   Trying to plot expression <v("/I0/net30" ?result "tran")>,
\o           which does not evaluate to an object that can be plotted,
\o           like waveform or parametric wave. Please refer to the
\o           Wavescan User Guide to see what all types of objects can be
\o           plotted in Wavescan. Expression which evaluates to only
\o           those type(s) of objects can be plotted

My ADE can use direct plot normally before and other schematics have no problem like this,I dont know why this occurs!With the output option,I have selected  save all and reset my state for some times.

Please help me!

I am using IC5141 usr6 and spectre from mmsim72