This error appears to only occur on Google Chrome. There is no error on Firefox 89.0.2 (64 bit)
I am using Canvas Version 91.0.4472.77 (Official Build) (64-bit) on Ubuntu 18.04.5 LTS
I have developed an LTI 1.1 deep linking tool that returns multiple gradable content items.
I am testing on our AWS Bitnami LMS powered by Moodle instance which uses Moodle 3.11 on a t3a.small instance size (2GB memory).
Moodle is able to connect to the tool and moodle accepts the links and displays them on the "Adding a new External tool" page.
After clicking "Save and return to course" moodle adds multiple content item links to a point (approx. 66 items) but then freezes on the next request and does not respond.
I have to kill the tab to be able to access moodle again, even in another tab.
I have attempted the following to try to narrow down the problem
Nothing in apache logs.
Nothing in Maria logs.
On a fresh course
Use "Adding a new External tool" Request deep linking with 58 gradable content items WORKS
Use "Adding a new External tool" Request deep linking with 14 gradable content items in same course HANGS after 12 content items added
Kill the tab then use "Adding a new External tool" Request deep linking with 1 gradable content item in same course WORKS
77 total gradable items created
On a fresh course
Use "Adding a new External tool" Request deep linking with 100 content items HANGS after 66 content items added
66 total gradable items created
This tells me that there cannot be a hard maximum of grade columns.
Tried upping PHP settings
max_execution_time = 320
max_input_time = 240
max_input_vars = 3000
memory_limit = 512M
Tried upping instance size
From t3a.small (2GB memory) to t3a.large (8GB memory) and increased PHP settings above more.
I could not find any reference anywhere to a maximum number of grade columns or maximum LTI content items.