Question: After I ran the update from Magento 2.2.8 to Magento 2.3.2, I am getting this error whenever I run a CLI command like upgrade or cache,

> 
> main.CRITICAL: Type Error occurred when creating object: Magento\Framework\Interception\Config\Config, Return value of Magento\Framework\Interception\Config\CacheManager::load() must be of the type array or null, string returned [] []
> 
> 
> 

Any idea how to solve that?

Thanks!

Answer: 
I was having the same issue and I did everything to work this out, but with no success.

It's showing me this error:
gallery.js:298 Uncaught TypeError: settings.$elementF.fotorama is not a function
at UiClass.initGallery (gallery.js:298)
at UiClass.initialize (gallery.js:139)
at UiClass.initialize (wrapper.js:109)
at UiClass (class.js:49)

I found out there was an external script that I used to add the WhatsApp chat that was conflicting. I just took off the script and guess what?

This is the damn script:

```
<script async data-id="68933" src="https://cdn.widgetwhats.com/script.min.js"></script>

```

I would suggest you check if you have any external scripts on your Magento 2 Design Configuration admin or you can try to check on your page whether one or more jquery with different versions are loaded.

It may be different jquery versions are conflicting with fotorama.
I was also faced same problem in my site. Please check on your page if any additional jQuery file has been added with another version. Because in my case different jQuery version were conflicting fotorama.