LESSCompilerException Error when accessing GDPR Cookie Consent Setup from Administration

STEPS TO REPRODUCE
Environment: Windows 10 Pro 64bit, Chrome 89, using an instance of XWiki 13.1 on Oracle 19c, Tomcat 9.0.43, GDPR Cookie Consent 1.2.5
Install GDPR Cookie Consent application
Go to Administer Wiki > Other > GDPR Cookie Consent Setup
Observe the console
EXPECTED RESULTS
The page is loaded right away. No errors are displayed in console.
ACTUAL RESULTS
The page is not loaded on the first click. In console there is the following stacktrace:
2021-03-10 15:50:53,946 [http-nio-1115-exec-8 - http://localhost:1115/xwiki/bin/ssx/CookieConsent/WebHome?language=en&docVersion=1.1] ERROR o.x.l.i.c.DefaultLESSCompiler  - Error during the compilation of the resource [org.xwiki.lesscss.internal.resources.LESSObjectPropertyResourceReference@f177eeba].
org.xwiki.lesscss.compiler.LESSCompilerException: Failed to compile the resource [org.xwiki.lesscss.internal.resources.LESSObjectPropertyResourceReference@f177eeba] with LESS.
        at org.xwiki.lesscss.internal.compiler.CachedLESSCompiler.compute(CachedLESSCompiler.java:114)
        at org.xwiki.lesscss.internal.compiler.CachedLESSCompiler.compute(CachedLESSCompiler.java:50)
        at org.xwiki.lesscss.internal.cache.AbstractCachedCompiler.getResult(AbstractCachedCompiler.java:137)
        at org.xwiki.lesscss.internal.cache.AbstractCachedCompiler.getResult(AbstractCachedCompiler.java:85)
        at org.xwiki.lesscss.internal.compiler.DefaultLESSCompiler.compile(DefaultLESSCompiler.java:66)
        at com.xpn.xwiki.web.sx.SxDocumentSource.getContent(SxDocumentSource.java:141)
        at com.xpn.xwiki.web.sx.AbstractSxAction.renderExtension(AbstractSxAction.java:86)
        at com.xpn.xwiki.web.sx.AbstractSxAction.render(AbstractSxAction.java:142)
        at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:561)
        at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:258)
        at com.xpn.xwiki.web.LegacyActionServlet.service(LegacyActionServlet.java:104)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:733)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:122)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.xwiki.wysiwyg.filter.ConversionFilter.doFilter(ConversionFilter.java:109)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.xwiki.container.servlet.filters.internal.SetHTTPHeaderFilter.doFilter(SetHTTPHeaderFilter.java:63)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.xwiki.container.servlet.filters.internal.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:208)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.xwiki.container.servlet.filters.internal.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:111)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.xwiki.resource.servlet.RoutingFilter.doFilter(RoutingFilter.java:132)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
        at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:687)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:346)
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:887)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1684)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: com.github.sommeri.less4j.Less4jException: Could not compile less. 2 error(s) occurred:
ERROR 7:7 no viable alternative at input '$' in ruleset (which started at 5:1)
 6:   position: fixed;
 7:       ${settings.getProperty('position').value}: 10px;
 8:     left: 50%;

ERROR 7:7 missing EOF at '$' in stylesheet (which started at 1:1)
 6:   position: fixed;
 7:       ${settings.getProperty('position').value}: 10px;
 8:     left: 50%;

        at com.github.sommeri.less4j.core.ThreadUnsafeLessCompiler.toAntlrTree(ThreadUnsafeLessCompiler.java:136)
        at com.github.sommeri.less4j.core.ThreadUnsafeLessCompiler.doCompile(ThreadUnsafeLessCompiler.java:101)
        at com.github.sommeri.less4j.core.ThreadUnsafeLessCompiler.compile(ThreadUnsafeLessCompiler.java:85)
        at com.github.sommeri.less4j.core.DefaultLessCompiler.compile(DefaultLessCompiler.java:56)
        at org.xwiki.lesscss.internal.compiler.less4j.Less4jCompiler.compile(Less4jCompiler.java:67)
        at org.xwiki.lesscss.internal.compiler.CachedLESSCompiler.compute(CachedLESSCompiler.java:108)
        ... 48 common frames omitted
2021-03-10 15:51:03,318 [http-nio-1115-exec-1 - http://localhost:1115/xwiki/bin/admin/XWiki/XWikiPreferences?editor=globaladmin&section=GDPR%20Cookie%20Consent%20Setup] WARN  .o.i.DefaultObservationManager - The [org.xwiki.localization.wiki.internal.OnDemandDocumentTranslationBundle] listener is overwriting a previously registered listener [org.xwiki.localization.wiki.internal.ComponentDocumentTranslationBundle] since they both are registered under the same id [localization.bundle.document:xwiki:CookieConsent.Translation]. In the future consider removing a Listener first if you really want to register it again.
However, the page loads if it's clicked again.
Tested on both XWiki 13.1 and 12.10.4.
xwikisas / application-cookie-consent

LESSCompilerException Error when accessing GDPR Cookie Consent Setup from Administration #30
