I too had the same problem when I was testing my plugin that I made.
The way to fix it was to move the plugin into the project (ue 5.3.2). It should look roughly like this:
YourProject/
├── Plugins/
│ └── YourPlugin/
│ ├── Binaries/
│ └── ...
├── ...
After moving the plugin, the error disappeared and everything worked correctly.