Magento 2.3 → 2.4 Upgrade — Real Problems Stores Face (And How to Avoid Them)

Upgrading from Magento 2.3 to Magento 2.4 is not just a version update — it is a major architecture, security, and dependency shift.

Many store owners assume:

“It’s just an upgrade — it should be simple.”

But in real-world projects, most issues happen because:

• Old modules break
• Server requirements change
• Payment flows fail silently
• Elasticsearch becomes mandatory
• PHP version upgrade impacts custom code

This guide explains the real problems stores face during Magento 2.3 → 2.4 upgrades — and how to prevent them.

Real Problem #1 — Elasticsearch Becomes Mandatory

What Changes

Magento 2.4 removes MySQL search completely.
Elasticsearch is required.

What Breaks

• Search stops working
• Category product listing fails
• Layered navigation crashes
• Admin product grid search issues

Why Stores Get Stuck

Many Magento 2.3 stores never configured Elasticsearch.

How To Avoid

✔ Setup Elasticsearch before upgrade
✔ Test search indexing
✔ Validate category filters
✔ Reindex large catalogs properly

Real Problem #2 — PHP Version Compatibility Issues

Magento 2.4 requires newer PHP versions.

Common Issues

• Custom modules stop working
• Deprecated functions crash pages
• Checkout customizations break
• Old payment extensions fail

Real Scenario

Custom extensions written for PHP 7.2 → break in PHP 8.x.

Prevention

✔ Run PHP compatibility scan
✔ Audit custom modules
✔ Replace outdated extensions

Real Problem #3 — Third-Party Extensions Break

This is the #1 real-world upgrade failure cause.

Why This Happens

Many extension vendors:

• Stop supporting old versions
• Delay new version compatibility
• Change database structures

What Usually Breaks

• Payment gateway modules
• Shipping integrations
• ERP sync modules
• Marketing automation tools

Prevention

✔ Extension compatibility audit
✔ Replace abandoned modules
✔ Test in staging environment

Real Problem #4 — Database Upgrade Failures

During upgrade:

• Schema updates run
• Data patches apply
• Table structures change

Risks

• Partial upgrade failure
• Data mismatch
• Order table issues
• Admin panel crashes

Prevention

✔ Full database backup
✔ Test upgrade on staging copy
✔ Validate upgrade scripts

Real Problem #5 — Checkout & Payment Failures (Silent Killers)

Sometimes checkout looks fine but:

• Payment callbacks fail
• Orders not saved
• Email triggers fail
• Payment success but order missing

This is extremely dangerous — revenue loss risk.

Prevention

✔ Full checkout scenario testing
✔ Sandbox payment testing
✔ Order workflow validation

Real Problem #6 — Composer Dependency Conflicts

Magento 2.4 updates many core libraries.

What Happens

Composer conflicts:

• Prevent upgrade
• Break deployment
• Create version mismatches

Prevention

✔ Clean composer dependencies
✔ Remove unused modules
✔ Validate dependency tree

Real Problem #7 — Performance Drops After Upgrade

Many expect performance boost — but sometimes opposite happens initially.

Reasons

• Cache misconfiguration
• Elasticsearch not tuned
• Old indexing setup
• Server not optimized

Prevention

✔ Redis + Varnish tuning
✔ Elasticsearch optimization
✔ Indexer configuration review

Real Problem #8 — Admin Panel Errors

Common After Upgrade:

• Product save errors
• Category loading issues
• Attribute conflicts
• UI component failures

Usually caused by:

• Old admin customizations
• Outdated JS dependencies

Quick Decision Guide

Upgrade Immediately If

• Security patches missing
• Payment gateway unsupported
• Hosting PHP forcing upgrade
• Version reaching end-of-life

Plan Upgrade If

• Store stable
• Latest 2.3 patch installed
• No security alerts
• Extensions actively supported

Biggest Hidden Risk — Skipping Upgrade Too Long

Risks include:

• Security vulnerabilities
• PCI compliance issues
• Payment gateway deprecation
• SEO performance decline
• Hosting incompatibility

Pro Tip — Why Most 2.3 → 2.4 Upgrades Fail

Not because of Magento.

Because of:
❌ No pre-upgrade audit
❌ No extension compatibility testing
❌ No staging testing
❌ No rollback planning

Recommended Upgrade Approach

Phase 1 — Audit

Check:

• Extensions
• Custom modules
• Server
• Database size
• Integrations

Phase 2 — Staging Upgrade

Test everything before live.

Phase 3 — Controlled Go Live

Low traffic window deployment.

Phase 4 — Post Upgrade Monitoring

First 30 days critical.

Should You Upgrade From Magento 2.3 Now?

In most cases → Yes
Magento 2.3 is outdated and risky long-term.

But upgrade must be:
✔ Planned
✔ Tested
✔ Monitored

Need Help Evaluating Magento 2.3 → 2.4 Upgrade Risk?

Before upgrading, it’s best to run a full upgrade risk audit.

👉 Start With Free Magento Upgrade Risk Audit
👉 Talk To Magento Upgrade Specialist

FAQ

Is Magento 2.3 to 2.4 upgrade risky?

It can be — mainly due to extensions and server requirements. Proper audit reduces risk significantly.

Can Magento 2.3 to 2.4 upgrade be done without downtime?

Yes — using staging + controlled deployment strategies.

How long does Magento 2.3 to 2.4 upgrade take?

Typically 3–8 weeks depending on complexity.

Final Thoughts

Magento 2.3 → 2.4 upgrade is a business-critical upgrade, not just technical maintenance.

Done right → Improves security, performance, scalability.
Done wrong → Can cause revenue loss and downtime.