Every time when I switch branches following error occurs, and I must repeatedly try to switch branch.

{{git -c diff.mnemonicprefix=false -c core.quotepath=false checkout develop
fatal: Unable to create 'C:/projects/mrb/.git/index.lock': File exists.

If no other git process is currently running, this probably means a
git process crashed in this repository earlier. Make sure no other git
process is running and remove the file manually to continue.

Completed with errors, see above.}}

But there is NO other git processes on whole my computer.
I think it is because Sourcetree itself tries to refresh branch and blocks its branch switching.

The same with merge, commit and so on.

Please, can SourceTree understand that there is only it who uses the repo and simply wait for another its own thread which is refreshing repo in background?