Intermittent Subscription Billing API timeouts

I’m seeing repeated API timeouts today, 10 September 2026, starting around 14:32 UTC. They are delaying payment verification in my application.

Affected endpoints:

• GET /subscription/6aa2befc4f2190c060fbe6f7
• GET /invoice/6aa2befc4f2190c060fbe6f8
• GET /subscription/6aa2c6d84f2190c060fbef85

At approximately 15:09:57 UTC, I tested two requests sequentially from my production server:

• The first subscription lookup timed out after 30.07 seconds.
• The second succeeded with HTTP 200 in 0.29 seconds.

Earlier requests sometimes succeeded too, so the issue appears intermittent or record-specific. The payment-failure webhook arrived successfully; the timeouts occurred during subsequent API reads.

Could you investigate why these API requests are timing out?

Thanks,
Sven

Hello Sven,

Thanks for reaching out and for the detailed information, including the affected endpoints, timestamps, and response times.

Can you please check now? It should be working fine. API Calls shouldn't be failing now. If they are still failing, please let us know.

“Please check now” does not address the problem. These failures delayed payment verification and license delivery to my customers. This has a direct impact on my business.

The issue was intermittent. A successful request now does not establish that it has been fixed.

Did your team identify the root cause and apply a fix, or did you only check that the API was responding? Please explain what caused the failures and what action was taken.

I also found this error from September 10 at 15:31:16 UTC:

GET /invoices/6aa2befc4f2190c060fbe6f6?page=1&limit=100

HTTP 400:

{"status":"error","message":"Cannot read properties of undefined (reading 'time_zone')"}

This is an internal error returned by Pabbly. Please investigate whether it is connected to the timeouts.

I need a concrete technical explanation and confirmation of corrective action. If necessary, please escalate this to your engineering team.

thanks so much

We sincerely apologize for the inconvenience and the impact this issue had on your payment verification and license delivery.

The failures were caused by an issue in our backend at the time. Our development team investigated the issue and has since fixed it.

We understand that a successful request afterward does not, by itself, confirm that the intermittent issue was resolved. The necessary corrective changes have now been applied by our development team, and we will continue to monitor the API to ensure that the issue does not recur.

We sincerely apologize again for the inconvenience caused.

Hello Sven,

I hope you’re doing well. I just wanted to follow up regarding our last message.

Thanks for following up.

The API appears to be working again, but my main question is still unanswered.

What exactly caused the timeouts, and what did your development team change to fix them?

Also, was the Cannot read properties of undefined (reading 'time_zone') error related to the same issue?

Since this affected payment verification and license delivery in production, I’d appreciate a concrete technical explanation rather than just confirmation that it is working now.

Thanks,
Sven

Hello Sven,

It was a backend database issue due to which the connections to Pabbly Subscription and Billing softwares were not get connected properly. The team has fixed the issue with the database, and it should not occur now.

Regarding your second concern, can you tell us the API request that you are executing when you get this error?

The API request is already included in my previous reply (#3):

GET /invoices/6aa2befc4f2190c060fbe6f6?page=1&limit=100

It returned HTTP 400 at September 10, 15:31:16 UTC with:

{"status":"error","message":"Cannot read properties of undefined (reading 'time_zone')"}

Thanks,
Sven

Hello Sven,

There was a downtime occurred on 10th September due to which the API request cannot processed on that day.