Any issues on upgrade XAMPP 1.8.3 to 5.6.12

[pgikkas]

Are there any obvious issues on upgrading from XAMPP 1.8.3 to 5.6.12.
This is on Win 8.1 laptop. The 1.8.3 works well although there are sporadic PHP issues i was hoping to eliminate.
Is the change from MYSQL to MARIADB of any consequence? Does phpMyAdmin work with MARIADB? Does MARIADB read a MYSQL created DB?