Unable to load a hierarchy...

Dear All,

I'm working with SAP NetWeaver 7.3 system and I'm unable to load hierarchies for Cost Center (0COSTCENTER), Profit Center (0PROFIT_CTR) and GL Account (0GL_ACCOUNT). I get following error message:

1. Why am I unable to load any hierarchy for Cost Center or Profit Center or GL Account?

2. How should I be able to load hierarchy successfully?

3. What should I do to get rid of this error message?

Many thanks!

Tariq Ashraf