... get past the error "The website encountered an unexpected error. Please try again later."

Hello,

I'm getting a blank page saying "The website encountered an unexpected error. Please try again later." when I try to import a currency (Currency module).
In the error log I see the following:

"Error: Call to undefined function Commercie\Currency\bcdiv() in Commercie\Currency\Currency->getRoundingStep() (line 187 of /home/deb71460n10/domains/.../public_html/vendor/commercie/currency/src/Currency.php) #0 /home/deb71460n10/domains/.../public_html/modules/currency/src/ConfigImporter.php(197) ........."

The strange thing is that it works locally. At first I thought it was a problem with composer, but I've made sure the modules folder, composer.json, composer.lock and the vendor map are the same locally and on the server.

Any idea what could cause this?