Fixing E_DEPRECATED Notice Errors After Upgrading from Evolution 1.0.12 to 1.0.13

Upgrade failures that start with Use of undefined constant E_DEPRECATED are strong signs that the runtime environment and the target build disagree about available PHP features or expected constants. Once notices appear too early, they often cascade into session and header warnings.

Why the whole site can appear broken

The initial notice sends output before headers are finalized. After that, session startup and redirect logic begin to fail, making the update look much worse than the original compatibility problem.

What to verify

• the exact PHP version on the host
• whether the target Evolution build expects constants or behaviors missing on that runtime
• custom patches in bootstrap files that now run too early

In upgrade work, the first warning usually matters more than the last one. Fix the earliest compatibility notice first, and many of the later header errors disappear automatically.