Thanks for your reply.
After updating to the following versions, its working without any error :
External Tools 18.104.22.168703061529
OpenSTM32 Remote debugging support 22.214.171.124703061529
The software update is complicated in the way it shows the installed and updated components necessary for development based on STM32 platform.
Are the following components necessary for development based on STM32 platform(see snapshot for details) :
Subversive SVN Connectors
Subversive SVN Team Provider
SVNKit 1.8.12 Implementation (Optional)