Creating Tasklist tab, a severe problem is being faced

In creating Task list tab, a severe problem is being faced by us. At the time of our creating Task list tab, the following error message appears in task space.

Since we are almost new ones, none of us can even guess what the problem is.

We have already made several efforts like restarting the application server, clearing the cache and many other things that we can. Unfortunately, the problem remains all the same. It is where it has been even after our attempts.

Though we have tried we are unable to view even the logs of this unexpected error. Some of us have already come across some posts regarding this sort of problem. Yet none of us is successful. Is there anyone from techyv.com to help on the issue mentioned above?

We will remain grateful if someone here gives a real solution to this issue.