Search stopped working

Hello, and thanks again for both a slick plugin and great support.
Our PDb search function has abruptly stopped working. Not at all sure why, but I have been making lots of changes to the site. Most of them seemingly unrelated to PDb. I’d appreciate any guidance or suggestions you can make.
I have search enabled on multiple pages with short code like this:
[pdb_list fields=”first_name, last_name, house, phone” orderby=”last_name” filter=”phone!&currentresident=Yes” list_limit=”150″ search=true]
and this:
[pdb_list fields=”last_name, zip, id, house, phone, adult_1, cellphone1, email1, resident2, cellphone2, email2, adult3, cellphone3, email3″ orderby=”last_name” list_limit=”250″ class=”onecolumn-page” filter=”currentres=yes” template=indivconttmp1 search=true]
I’ve recently been playing w/ the [pdb_search target_instance= target_page= ] shortcode, but it didn’t meet our needs and I’ve stopped using that shortcode.
Search was working beautifully on the pages that use the default templates, but then suddenly stopped working a couple of days ago. Little swirly progress wheels appear and continue to swirl indefinitely. Errors look like these:

[23-Sep-2015 04:37:51] PHP Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 936692 bytes) in /blog/wp-includes/functions.php on line 384
[23-Sep-2015 04:39:42] PHP Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 936562 bytes) in /blog/wp-includes/functions.php on line 384
[23-Sep-2015 11:32:39] PHP Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 937774 bytes) in /blog/wp-includes/functions.php on line 384

Our site is small, less than 100 pages, very little traffic, password protected, maybe 100 users. Our pdb database is small, fewer than 200 records and maybe 20 fields; 6 or so groups.
Any suggestions?
with sincere appreciation and best regards,
BCC

https://www.ads-software.com/plugins/participants-database/