Any ideas why Indians maybe denied Ukrainian visas for "invitation letters" they got from agencies in Ukraine?

This lady from Ukraine who works with OdessaApts.com says, "We have had a number of Indian citizens who have attempted to get invitation letters from Ukraine and were denied Visa requests." Earlier, she said, "You may not be able to visit Ukraine being a citizen of India." This is regarding getting a Ukrainian visitor visa for an Indian citizen living and working in the US. She frightened me. It looks like I cannot visit that country, but I don't see why, because offically I don't see any problems. No website says there are any problems with Indians getting visitor visas to Ukraine. The diplomatic relations between the two countries are fine, and Ukrainians happen to benefit more from trade with Indians than Indians do from them. I'm wondering if the invitation letter will have to come from Ukraine itself or if it can come from any any agency within the US that works with Ukrainian visas and travel. Also wondering why those Indians were refused visas, if not for their ethnicity!