After my PhD, I continued with a postdoc in my PhD lab. The topic and the numerical method was quite different than my PhD and I had to read up quite a bit of literature to start the new work. However, as I was also involved in other projects as well, I took around nine months to complete the work. While writing the paper, I have discovered that I have done a major mistake in my simulation parameters and model. The work cannot be published unless I correct the mistakes and run the simulations again which would take at least a month more.
I was asked to submit the manuscript for review by the advisor and other collaborators by next week. However, now I can't write the paper with the errors. And I have to rerun the entire work again.
What do I do now? I am almost a year into my postdoc, and I shouldn't have made such errors. How do I approach this and what do I tell my advisor and collaborators?