If you are getting that error, then the upload probably was not successful!
You probably need to find the broken question in the database, and delete it.
It probably should not be the case that one bad quesition in the database stops the question bank from displaying. That seems like a bug. Which version of Moodle?
Sir the version is moodle 3.5 . Sir I am new to moodle can you please navigate me how to do that
I highly discourage any direct database modification if you are not a developer, as there are a lot of things that can go wrong and your Moodle may incur irreparable damage.
I have created MDL-62811 so that we work on a patch to not stop loading the question banks page when there is a corrupted question.
Is it possible that you share the file you used for the import?