Prestashop 1.7.1.1 Unable to create product with combination

[Lyion]

Hello and good day. I am facing a very annoying issue while creating the product. I am using Prestashop 1.7.1.1 with Inmotionhosting. When i want to add a combination such as colour, i clicked the "generate" button but it didn't show up anything. After refresh the product page, it showed up but unable to save the product. I have attached few pictures with the error and also video. Anyone able to help me? I have tried a lot of way and contacted with the server hosting. But none of them able to help.

 

 

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Try disabling opcache or alike then empty cache by clicking the icon in performance setting page then reload ; might works.