Loop merging problem

Hello, I want to read excel tables in batches and use loop to merge the tables of all files into one table. The process is as follows, but the following message appears:

ERROR Loop End 4:20 Execute failed: Input table’s structure differs from reference (first iteration) table: Column 9 [初期壓差(COA) (String)] vs. [過濾循環PUMP壓力 (String)]