On one of our sites we seem to have a strange interaction of Smart Search and Sourcerer. Search is working ok except for when we search for the word "test". Then we get this error message:
WebAssetManager is locked, you came late
As far as we can see , this is the only word that throws this error.
Because Sourcerer is mentioned in the stack shortly before the error appears, we tried switching off Sourcerer. After doing that, we can search for "test" without problems.
In the confidential info you'll find two develop locations where we restored the same backup of our site. On one of them Sourcerer is activated, on the other one it is disabled.
You probably have custom code somewhere - that is being placed through Sourcerer - that is trying to add scripts or styles to the page. On the search page, the moment Sourcerer gets to see that code and execute it, you can no longer add scripts/styles.
Best is to add checks to your custom code to see if the Joomla WebAssetManager is still open.