@santosh_singh and @Pendu have you read this topic
To summarise the 79 posts, it appears that macOS’s 10.13.6, 10.14.1 and 10.14.6 on older mac machines have an issue with Manager after Ver 21.1.6. There is discussion on how you can go back to Manager Ver 21.1.6 but that solution may not be available in all cases.
Upgrading your mac machine may be the only solution based on this Lubos comment:
“I’m not quite sure whether this issue will be fixed. Both High Sierra and Mojave no longer receive bug fixes from Apple. I’m awaiting guidance from third-party programmer to see if this is fixable and whether we can continue supporting High Sierra and Mojave or we will have to bump up minimal requirements to Catalina or higher.”