Finally, I managed find something more specific about this issue: If the user opens any question in any survey and edit it trying to open the resources manager from within the question editor, everything comes back to normal and the kcfinder window works just fine. After that, you the user can use the kcfinder in any other option where available (e.g. to edit label sets or anything else).
BUT if the user attempts to open the kcfinder before opening it in some question within any survey (e.g. trying to modify some label set from the "Configuration" menu), then the message appears saying that the user does not have permissions, or the kcfinder window does not open properly or correctly. I hope this helps.

Additional information on the same issue: when trying to access "Resources" from the menu "Structure" in any survey, I get an incomplete window (see the snapshot) and an endless loop that at some point results in a message saying that the page does not respond.

snapshot 2023-11-19 094450.png (57,742 bytes)   

snapshot 2023-11-19 094450.png (57,742 bytes)   

Sorry... I meant "...from the menu "Settings". Not "Structure"...

It has been found that:

1. In Firefox, KCFinder works just fine. The issues is related to Chrome.
2. The new LimeSurvey version 7.0.5 has not resolved the Chrome issue with KCFinder.

Further testing confirms that the issue appears to be specific to Chromium-based browsers.
Test results:

• Firefox: KCFinder works normally in both regular and private browsing windows.
• Google Chrome: KCFinder remains incomplete and the LimeSurvey tab eventually becomes unresponsive, both in regular and Incognito mode.
• Microsoft Edge: the same problem occurs; KCFinder remains incomplete and the tab becomes unresponsive.

The problem persists after:

• upgrading LimeSurvey to version 7.0.5;
• clearing the LimeSurvey frontend cache;
• clearing all LimeSurvey site data in Chrome;
• disabling the browser cache through Developer Tools;
• testing in Chrome Incognito mode;
• disabling hardware acceleration in Chrome;
• testing the Resources page in a separate browser tab.

In Chrome Developer Tools, the Network panel shows no failed requests, HTTP errors or red entries; the required files appear to load normally. The Console displays the following message:
PJAX -> No JSON found. If you expected it there was an error

Only the tab in which KCFinder is opened becomes unresponsive. Other LimeSurvey administration tabs remain fully functional.

Therefore, this does not appear to be a server-side, PHP-session, file-permission or browser-cache problem. The behaviour points to a KCFinder JavaScript compatibility problem affecting Chromium-based browsers, while Firefox remains unaffected (Edge version: 149.0.4022.80, 64 bit, Chrome version: 149.0.7827.156, 64-bit).

Further testing confirms that the issue appears to be specific to Chromium-based browsers and is not limited to my self-hosted LimeSurvey installation.

Self-hosted installation

The issue occurs in LimeSurvey 7.0.5 on my Ubuntu-based installation:

• Firefox: KCFinder works normally in both regular and private browsing windows.
• Google Chrome: KCFinder remains only partially rendered and the LimeSurvey tab eventually becomes unresponsive, both in regular and Incognito mode.
• Microsoft Edge: the same problem occurs; KCFinder remains incomplete and the tab becomes unresponsive.

The problem persists after:

• upgrading LimeSurvey to version 7.0.5;
• clearing the LimeSurvey frontend cache;
• clearing all LimeSurvey site data in Chrome;
• disabling the browser cache through Developer Tools;
• testing in Chrome Incognito mode;
• disabling hardware acceleration in Chrome;
• testing the Resources page in a separate browser tab.

In Chrome Developer Tools, the Network panel shows no failed requests, HTTP errors or red entries; the required files appear to load normally. The Console displays the following message:

PJAX -> No JSON found. If you expected it there was an error

Only the tab in which KCFinder is opened becomes unresponsive. Other LimeSurvey administration tabs remain fully functional.

LimeSurvey Cloud installation

I also reproduced exactly the same behaviour in the LimeSurvey-hosted installation provided through a free account on limesurvey.org:

• in Google Chrome, KCFinder remains partially rendered and the page becomes unresponsive;
• in Firefox, KCFinder loads and works normally.

Since the problem is reproducible both on a self-hosted Ubuntu installation and on the official LimeSurvey-hosted service, it does not appear to be caused by the local server configuration, PHP settings, file permissions, ModSecurity, browser cache or the upgrade procedure.

The results point to a KCFinder JavaScript compatibility problem affecting Chromium-based browsers, while Firefox remains unaffected.

I can not reproduce it in Chrome, neither in any CE version 6 or 7 , nor in v6 on LimeSurvey Cloud.
Can you try using another Chrome version? Because it is sounds like a bug in your Chrome version or (less likely) some proxy/firewall issue.