[TYPO3-english] Sudden php warnings in backend generated by Fluid - TemplateParser.php

[Albert van der Veen]

Hi all,

All of a sudden the backend of a 4.5.19 site is flooded with these 
warnings and an error in the frontend is generated, preventing any output:

PHP Warning: preg_match() [<a 
href='function.preg-match'>function.preg-match</a>]: Compilation failed: 
internal error: previously-checked referenced subpattern

in file:

fluid/Classes/Core/Parser/TemplateParser.php line 769

Googling returns realted errors, for example here: 
http://drupal.org/node/1286046, suggesting it might be related with an 
update of the PCRE library.
However, according to my hosting provider nothing was changed.

Any clues?

Thanks,
Albert