MSP import issues with material res assignments in P6 EPPM V8.3?

Are there any know issues with importing of MS Project with tasks having assignments of material type of resources in P6 Web version 8.3??? Here is what I am experiencing..........

1. In V8.3 Web version (EPPM), I could import MS Project (created in MSP 2010) with 600 tasks, many levels and complex dependencies.

2. After I loaded the MSP project with labor and material types of resource assignments, import failed. Log file did not point specifically to any error.

3. To narrow down the issue, I deleted assignments of all material type of resources and the import was successful

4. Then I added just one material resource assignment and it was again failed with no specific message in log file.