As of March 2018, Shopify stopped supporting any admin related issues when using Internet Explorer 11. The reason behind this is because Microsoft launched "Microsoft Edge," which replaced Internet Explorer 11. You will want to use one of the supported browsers on your PC which should resolve the admin related issues you're experiencing:
If you're still experiencing issues after installing one of the support browsers, then let me know.
We stopped supporting Internet Explorer 11 for admin related issues, meaning that storefronts should still work on Internet Explorer 11, so long as the theme you are using is optimized for that browser. As it is an older browser, it will be harder to optimize the theme, though, doing so should help resolve the issues you're seeing. Are you using a Shopify free theme, or are you using a third-party theme? If a Shopify theme, then I can gather further details on the issues you're experiencing, verify the account, and escalate the issue up to our theme support. However, if you're using a third-party theme, then it will require reaching out to the theme developer or hiring a Shopify Expert.
That'd be outside my area of expertise I'm afraid; however, if you have a Plus account, the accounts Merchant Success Manager should be able to help connect you with either a developer, or our FED team to see what can be setup. If you're unable to connect with the stores MSM, or if the store does not have an MSM, let me know as I can verify the account to see who would be the best person to connect you with.