Database format, format of communication between PHP and texvc and PHP code is not touched. Upgrade shouldn't bring any problems.
Changes: * cases envinonment supported * \left and \right must be followed by delimiters, and must balance. It could generate some parse errors on previously accepted input. It could happen in two cases: * this input was invalid latex anyway * some valid delimiters is not on texvc's list * \big \bigg \Big \Bigg supported (they must be followed by delimiters) * \ddots supported
Please update test.wikipedia.org, and if no bugs are found in the next few days, update all Wikipedias.