Weird 405 and 404 error while uploading excel files using Laravel Excel

It sounds like you're encountering HTTP errors when trying to use the Excel::import() function from the Laravel Excel package. A 404 error typically indicates that the requested resource could not be found, while a 405 error means that the HTTP method used is not allowed for the requested resource.

Here are some steps you can take to troubleshoot and resolve the issue:

1. Check Routes: Ensure that the route you are posting to for the import exists and is defined in your web.php or api.php route files. A 404 error could mean that the route is not correctly defined.

2. Check HTTP Method: Make sure that the form or AJAX request that is submitting the Excel file is using the correct HTTP method (usually POST) that your route is expecting. A 405 error could be caused by using a GET request on a route that only accepts POST requests.

3. Middleware: If you have any middleware applied to the route, ensure that it's not interfering with the request. Sometimes middleware can reject requests, resulting in 404 or 405 errors.

4. Permissions: Since you're on a UNIX server, check the permissions of the directories where the Excel files are being uploaded to ensure that Laravel has the necessary permissions to read and write files.

5. Error Logs: Check the Laravel logs in storage/logs/laravel.log for any detailed error messages that might give you more insight into what's going wrong.

6. Dependencies: Since you mentioned upgrading one of the Laravel Excel installations, ensure that there are no conflicting dependencies that might be causing issues. You can do this by running composer update and checking your composer.json file for any version conflicts.

7. Test Locally: If possible, try to replicate the issue in a local development environment. If the issue does not occur locally, the problem might be related to the server configuration.

8. Laravel Excel Configuration: Check the configuration settings for Laravel Excel in config/excel.php to ensure they are set correctly and haven't been changed inadvertently.

9. File Upload Size: Verify that the file you're trying to upload doesn't exceed the upload_max_filesize and post_max_size directives in your php.ini configuration.

10. Debugging: Temporarily add debugging code around the Excel::import() call to get more information about the request and any potential errors.

Here's a basic example of how you might debug the import process:

try {
    Excel::import(new YourImport, request()->file('your_file'));
} catch (\Maatwebsite\Excel\Validators\ValidationException $e) {
    $failures = $e->failures();
    foreach ($failures as $failure) {
        // Handle the failure details
        $failure->row(); // row that went wrong
        $failure->attribute(); // either heading key (if using heading row concern) or column index
        $failure->errors(); // Actual error messages from Laravel validator
        $failure->values(); // The values of the row that has failed.
    }
} catch (\Exception $e) {
    // Handle general exceptions
    Log::error($e->getMessage());
    return response()->json(['error' => $e->getMessage()], 500);
}

If none of these steps resolve the issue, it might be helpful to provide more specific error messages or stack traces from your logs to get more targeted help.