This error appears whenever trying to use the search feature, either via a block or the main module.

Fixed in https://github.com/ocproducts/composr/commit/5a9e40af9f02068ad51f10e3af1a75639cdd962d

The issue still persist. All 3 files have been changed and double checked/cross referenced with your edits.

Actually you found a separate issue.
Fixed in https://github.com/ocproducts/composr/commit/a9ac313eabd8c6e819251e9994de42acbd01de20

Things got worse, Chris. Now I cannot access my site - it's just blank. No CSS, just HEAD, BODY, HTML tags with nothing in them!

I'll revert back to the original files for now.

I have to consider this fixed, but if it really is an issue in the next patch release please re-open.
A blank site like that likely would have been caused by a corrupted PHP file, some kind of syntax error.

Ok, here's an update:

My white page issue was a fault of my own; something went wrong when saving the new files. I downloaded the entire 'fields' directory from git and replaced it with mine -- this has solved the white page issue.

However, now I receive a critical error every time I navigate to the search page.

Critical error – bailing out
PHP ERROR [1] Class 'FieldsSearchHook' not found in sources/hooks/modules/search/calendar.php on line 25

(see last note)

Try reuploading sources/search.php

No change.

I'm sorry my bugs are never straight forward :/

I'll take a look on your site and see if I can find something wrong.

Your site/pages/modules/search.php was from an older version. I fixed it.

Thanks! Everything seems to be working normally now.

I'm curious how you were able to change it without FTP access?

Commandr has file editing capability.