Hi @ashishkpaul,
There are a few different causes of the 200 error and some differnet solutions. Here are some steps that may solve this problem for you, please go through each one until the issue is resolved:
– Make sure that your Calendar page is set to the right page in the Settings > Viewing Events tab (no need to use shortcode on a page set as the default in the plugin settings)
– Try turning on/off “Strict compatibility content filtering” in Events -> Settings –> Viewing Events.
– Try turning on/off “Use frontend rendering” in Events -> Settings –> Advanced
– Try resetting Settings > Permalinks to Plain and then back to your custom style
– This particular error is usually a result of a plugin or theme conflict (usually caused by a caching or security plugin).. To test this, please try a different theme temporarily such as Twenty Seventeen (be sure to save any theme specific settings), or, disable all plugins and then check if the problem recurrs — then re-enable each one until you find which one caused the problem.
Let me know the results.