# Common problems

This document lists common integration issues encountered with Kustom Checkout (KCO), categorized by frequency.  It's not an exhaustive list but a summary of key problems observed.

## Re-initializing KCO

Do not re-initialize KCO without reloading the page. Use the `suspend/resume` method instead for order updates. Re-initialization prevents cleanup of listeners and iframes, leading to errors.

## Injecting the snippet

Ensure the Kustom Checkout snippet, obtained from the backend, is injected into the main page/frame.  Failure to do so can cause UI/UX and functionality issues.

## Detaching iframes

Re-creating or detaching iframes from the DOM can disrupt message passing between iframes, causing issues.  Important information is passed via iframe URLs.

## Using outdated libraries

Avoid modifying built-in browser functions, particularly with older libraries like Prototype.js.  Directly modifying these functions can cause Kustom Checkout to malfunction.  Use local functions if necessary to replicate browser functionality.

## Styling iframes

Kustom Checkout iframes use inline styles, which have high specificity.  Merchants should avoid applying global styles to all iframes, especially using `!important`, as this can conflict with Kustom's styles and prevent full functionality.

## Modifying iframe URLs

Modifying the iframe URLs used by Kustom Checkout can break the parsing of important information.

## Using `transform` on body

Applying the `transform` property to the body element can disrupt the positioning of the fullscreen iframe, causing issues with viewport coverage and content visibility.