It can come from different issues. Let's see here the different things you should check :

Step 1 : Convert your Project

If you started your project with the Blackmagic Plugin, then the project needs to be converted to BRAW Studio to be stable.
You can check this article to know how to do that.

Step 2 : Reset your Plugin Cache

In rare cases, Premiere Pro saves some old information about the plugin which makes it unstable with newer versions ..
To clean the Plugins cache, please start Premiere Pro and maintain the "Shift" Key pressed. You should get a message "Are you sure you want to reset your plugin caches ?" : answer Yes !

Step 3 : Clean your Media Cache

Open a new empty project in Premiere Pro, and then in the top menu : "Edit" -> "Preferences" -> "Media Cache.." : click on the "Delete.." button and then select "Delete all media cache files from the system."

Step 4 : If the previous solutions did not work

Contact us ! Here is an article which will show you how to generate this bug report ! Remember to with logs enabled before to send us the zipped logs !
Contact us here !