Hi,
Its a operating system related issue as discribed in the microsoft kb -
https://support.microsoft.com/en-us/help/2564571/-error-opening-installation-log-file.-verify-that-the-specified-location-exists-and-is-writable.-error-when-attempting-to-uninstall-an-application
work around this issue given is to stop and restart the Explorer.exe
kill the explorer.exe process from task manager and then in the task manager click on file>new task
Type explorer.exe and hit enter.
then try repairing the client again.
If this also dont work run cleanwipe and reinstall the SEP client.