SharePoint Online / Office 365 coding moves to Next Generation – Sandbox Coding Depreciated.

SharePoint developers are aware of Microsoft’s previous announcement in 2014 that depreciation of custom code in SharePoint sandbox solutions.  Time has come now, early this week, while working on sandbox solutons, “Activate” button against a sandbox solution with custom code was unavailable, and we see this alert: “Activation of solutions with sandboxed code has been disabled in this site collection. Contact your administrator to enable activation using the guidance published here.”

What does this mean to developers ?

Now, we need to repack wsps without server side codes and deploy solution. Please note, there is no restriction in deploying ‘sandbox solution’ as long as it does not contain server side coding which means No Code Sandbox Solutions (NCSS) continue to be supported.

Why this change ?

Since server side code is utilize server resources which Microsoft didn’t plan in office 365 / Sharepoint online and gave enough time to change coding habits to keep the code away from their platform. We feel this is a phenomena of today era where most of the apps are run using client side coding and app developers especially mobile apps, keep their code on their servers to take utlize their resources as it needs.

Here is the announcement from Microsoft

We started taking steps this week to complete the removal of code-based SharePoint sandbox solutions as part of the phased approach we announced in 2014 when we deprecated the feature.

At that time, we recommended that customers and partners transition their solutions to the add-in model or pure client-side development, which provide highly-scalable, cloud-first approaches to extending SharePoint. Since then, many customers have transitioned full-trust and sandboxed solutions to the add-in model, and their success and experiences are reflected in the samples and guidance of our Patterns and Practices initiative.

Detailed below are recent actions taken and what to expect next:

  • As part of the removal process, activation of new code-based sandbox solutions, as well as updates of existing solutions are no longer available.
  • In the coming weeks, running code-based sandbox solutions in SharePoint Online multi-tenant environments also will be disabled. Customers with these solutions should watch the Message Center and Service Health Dashboard (SHD) for details, timelines, and exception processes.

Note that currently, we do not plan to deprecate or remove support for declarative (no-code) SharePoint sandbox solutions.  For more detail, follow the information from Microsoft from following link :