Errors when upgrade phpBB 3.0.12 to phpBB3.1

I am going to upgrade my forums which are powered by phpBB.  The package I downloaded is automatic upgrade package. phpBB-3.0.12–3.1.0.zip

One is small forum, with most of the default settings. When I upgrade it as old way, the error came as below:

Fatal error: Composer dependencies have not been set up yet

Laterly, I found I just uploaded the folder “install”. The thing I missed is folder “vendor”.

Then, I uploaded both install and vendor folders to my forum root directory.

This error is gone and following upgrade procedures are smooth.

 

The second forum is much bigger. It has 681291 posts and a lot of modification I made on it.

When I tried to upgrade it. When I tried to download the modified files, errors shown:

Request-URI Too Large when updating

The official support forum said, I can put a directive into apache conf to increase the limit:

LimitRequestLine 8190

I did it and restart the Apache web server. The error still comes. I think the limit 8190 is not big enough. But the Apache guide defined that 8190 is the hard limit in Core.

I don’t know how to solve it, maybe I will try to upgade it in the virtual machine and use the other way to upgrade it.