Upon Subscribe to the out of stock product from front-end, in rare case you might encounter this "Something went wrong" error.
Why is that happen?
There are many cases behind this error, but overall common issue is cache. We use WP Nonces for security with ajax request, so here The meaning of the Nonce is “number used once” and a Nonce has a life time. If it is expired, the ajax request which contains a Nonce cannot be completed and hence that request fails where the result will be "Something went wrong".
By Default WordPress Cache(Plugin) designed to cache the page, here the cache page means pages including nonces, so after the expiry of nonce(it needs to assign new value but due to cache page new value will not loaded automatically) hence clearing the cache is the only option to recreate the nonce value.
What is the solution?
Simple, do set the cache timeout in your cache plugin settings, if you already setup cache timeout then reduce default value to lower(For Ex: if it is 12hours reduce it to 7 or 6 hours). Hope this will help to resolve your issue.
If you still facing some issues, please feel free to contact us by opening a support ticket here.