why the trajectory files can't be animated in Forcite?

Dear Sir or Madam:

Recently I conducted MD simulation using Forcite and after the job was completed, one trajectory .xtd was generated together with a hidden file .trj. One strange thing is: when I tried to open the ".xtd" file, you just can't animate it. It seems that the ".xtd" file and ".trj" file can't get connected. Even I restart the Material Studio or even the computer or re-run the job, the problem still existed. Before it was OK, the only difference is that the file genarated now is very large, greater than 7 GB.

Do you experence this before?

Thanks a lot in advance!

Best regards,

Wesley