Excel search prompts a message box for invalid row

Hi, I'm having trouble with my code. When clicking on the 'select file', it prompts a user form for user to fill in driver id, date range and 2 files to choose to search it on, roster and event file.
But when executing the search, it runs normally until it reaches cell B11, where it prompts the msg box 'invalid data on row 11'.
The problem here is after closing it, it inputs the cell value but populating the necell will prompt the msg box with the same text. This repeats for all following populating cells until it ends
Currently, only the 'clear table' and 'select file' buttons work, the rest are still in progress.

Right now there is only the search function for the roster file, so the same file can be used for the event file since no search function has been applied on that yet.

Edit: After some debugging, I realised that the output ran into some conflict with the preexisting validation subroutines. As such, I have marked it solved.