Hello,
I have tested CFA for a scale which includes 8 items in Mplus. The initial measurement model fits the data well except for RMSEA. To increase the model fit, i have added four residual covariances between items of this scale. But I am still getting low RMSEA (.09). I am wondering is there any source supporting the measurement model's validity despite the low RMSEA (.09) with strong CFI (.98), TLI (.97), and SRMR (.03) values.