Odd message when running some reports

Hi experts:

System lately shows a odd message when we try modifying a cost center group, running a reports and in others transactions.

The message is the following:

"Group M100 contains 3549 individual values or intervals. Options for checking master data are also active (see default settings). Obtaining master data information (existence check, texts) can considerably increase the run time.

Evaluate master data anyway?"

I have checked the standard hierarchy and I can't find out what the problem is. I can't see any wrong thing in the creation of the cost centers. The only extraordinary thing that I see comparing with oher customers where I have worked before is that we have thousands of cost centers here.

Could you help me, please?

Best regards

Jose