Sliding door will not open?

More then likely this is a door handle issue but if the handle is releasing then you have an issue with the door. I am attaching the process needed to remove the handle and door to find out what is going on inside the door.

Review this material and let us know what questions you have. However, i suspect you will need to open up the door and remove it in order to repair it.

Here is a guide that will help just removing the panel. This is not on a sliding door but it is the same process.

https://www.2carpros.com/articles/door-panel-removal

Thanks