INTEGRATION_DIRECTORY_HMI test - 500 Internal server error

When I test my RFC connection INTEGRATION_DIRECTORY_HMI, it is giving the following error.

500 - Internal Server Error

Application error occurred during request processing.

Details: Error [javax.servlet.ServletException: REQID not found].

Exception id: [000D600B942601060000010E000CA07A00041309B861DE0F]

The following are the the technical seetings for INTEGRATION_DIRECTORY_HMI RFC destination.

TargetHost: XXXXX.XXX

Path Prefix: /dir/CacheRefresh

Service No: 50100

When I went to SXI_CACHE, it seems to be fine.

Please help.

Thanks,

Samatha