No valid themes are found on this instance

Ok so after submitting this to bugs, I was instructed to post here so I hope someone can help with this issue. Searching the forums I found one reference to the same issue but did not see a resolution.

The following is the information that I submitted

Server
Windows Server 2012 R2 running IIS
8GB Ram

PHP Version
PHP 5.5

MySql Server
Version 5.1

Prev. Installation
SugarCRM CE 6.5.22

Current Installation
SuiteCRM 7.5.1 by way of Migration using the Upgrade path.

Although this message appears to be random I have noticed that they show up almost every time I create and new entry in a module and I click on save. It is also important to note that if I hit F5 when I get this error message “No valid themes are found on this instance” the page appears with not problems.

Any solution for this, I am also having the same issue(in new version of suitecrm).

I dont’ know if this has anything to do with the original issue but I did a fresh install of SuiteCRM (Latest Version) and I no longer get this error

I just fixed this on a clients instance.
when upgrading to 7.9.x I believe some of the old themes (SuiteR) have been discontinued.

to get your instance working again, open up config.php and find the default_theme key and replace the value with SuiteP

Apparently, the major email enhancements that were introduced with Suite 7.9 use a different underlying theme/display “technology” and the only theme currently available is Suite P (along with the compressed/tweaked variations mentioned elsewhere on this forum).

I have also encountered issues, even when doing a very basic Suite upgrade (e.g. 7.8.4 to 7.8.5).

Often times, if your CRM module structure is not overly-complex and without huge tables, you can actually save time and headaches by just doing a fresh install and data import, rather than an automated migration using third-party tools.

A fresh install is about mandatory when you are not doing incremental upgrades (i.e. you are leap-frogging several versions of Suite), where table structures, etc. may have changed.

It’s also good to keep in mind that 7.9 is brand new, so watch out for the initial [weekly] slew of updates/bug fixes.

Hi, updating a very old thread just in case someone else Google’s their way here.

In addition to changing the default_theme key in config.php to SuiteP, ensure that the disabled_theme key in config.php is not SuiteP and also the disabled_theme key in config-override.php is not SuiteP.