Hi, I am very new to RNA seq data analysis. I want to do gene enrichment analysis from the expression data used Limma. I followed the tutorials, but got the error.
Thank you in advance.
Tina
Welcome @T_Ngao
The tool is reporting a data input problem: the content of the SampleID values in two of the input files is not the “exactly” the same for some reason.
Tab over to the Details window and click to expand datasets 269 and 270 in the Inputs/Parameters table. Can you notice a difference in the SampleID field? This tool will expect the values to be identical. It is using that common key value to join the data together for the other manipulations.
You may need to back up a few steps to find where things went wrong. We have a guide here that covers the most common reasons for issues with these tools. → FAQ: Extended Help for Differential Expression Analysis Tools. The tool form is also really good – scroll down into the Help section to see examples of the files in plain text that you can compare to.
If you need more help, we can help to troubleshoot but will need to see the files (data files and your reference data files) at the detailed level. How to share your history for feedback is in the banner topic of this forum, also here. → How to get faster help with your question. You can generate the share link. post it back in a reply, then unshare once we are done.
Let’s start there! 
XRef → Hands-on: 3: RNA-seq genes to pathways / 3: RNA-seq genes to pathways / Transcriptomics