java.io.FileNotFoundException: C:\Program Files\Atlassian\Application Data\JIRA\data\avatars\
I've set up Jira to run through a reverse proxy using IIS, and applied SLL, following: https://confluence.atlassian.com/kb/proxying-atlassian-server-applications-with-microsoft-internet-information-services-iis-833931378.html
(I also have Confluence on the same server, and it has a problem displaying pages. Icons are fine)
In Jira, icons for issue types are not showing.

error log:
2018-08-30 08:09:32,090 http-nio-8080-exec-34 ERROR [o.a.c.c.C.[.[localhost].[/].[viewUniversalAvatarServlet]] Servlet.service() for servlet [viewUniversalAvatarServlet] in context with path [] threw exception
java.io.FileNotFoundException: C:\Program Files\Atlassian\Application Data\JIRA\data\avatars\10512_xsmall_ecbf9dac-6ba1-4e0f-a6a7-2ddb8b23acac.png (The system cannot find the path specified)
at java.io.FileInputStream.open0(Native Method)
at java.io.FileInputStream.open(FileInputStream.java:195)
at java.io.FileInputStream.<init>(FileInputStream.java:138)
at com.atlassian.jira.avatar.AvatarManagerImpl.getAvatarInputStream(AvatarManagerImpl.java:392)
at com.atlassian.jira.avatar.AvatarManagerImpl.lambda$processAvatarData$0(AvatarManagerImpl.java:367)
at com.atlassian.jira.avatar.OriginalAvatarFormatPolicy.getData(OriginalAvatarFormatPolicy.java:22)
at com.atlassian.jira.avatar.AvatarManagerImpl.processAvatarData(AvatarManagerImpl.java:365)
at com.atlassian.jira.avatar.AvatarManagerImpl.readAvatarData(AvatarManagerImpl.java:473)
at com.atlassian.jira.web.servlet.AvatarToStream.sendAvatar(AvatarToStream.java:29)
at com.atlassian.jira.web.servlet.ViewUniversalAvatarServletImpl.doGet(ViewUniversalAvatarServletImpl.java:42)
at com.atlassian.jira.web.servlet.ViewUniversalAvatarServlet.doGet(ViewUniversalAvatarServlet.java:20)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
... 44 filtered
at com.atlassian.servicedesk.internal.web.ExternalCustomerLockoutFilter.doFilter(ExternalCustomerLockoutFilter.java:56)
... 4 filtered
at com.atlassian.greenhopper.jira.filters.ClassicBoardRouter.doFilter(ClassicBoardRouter.java:62)
... 12 filtered
at com.atlassian.web.servlet.plugin.request.RedirectInterceptingFilter.doFilter(RedirectInterceptingFilter.java:21)
... 58 filtered
at com.atlassian.jira.security.JiraSecurityFilter.lambda$doFilter$0(JiraSecurityFilter.java:66)
... 1 filtered
at com.atlassian.jira.security.JiraSecurityFilter.doFilter(JiraSecurityFilter.java:64)
... 32 filtered
at com.atlassian.jira.servermetrics.CorrelationIdPopulatorFilter.doFilter(CorrelationIdPopulatorFilter.java:30)
... 5 filtered
at com.atlassian.servicedesk.internal.web.CustomerContextSettingFilter.lambda$invokeFilterChain$0(CustomerContextSettingFilter.java:181)
at com.atlassian.servicedesk.internal.api.util.context.ReentrantThreadLocalBasedCodeContext.rteInvoke(ReentrantThreadLocalBasedCodeContext.java:137)
at com.atlassian.servicedesk.internal.api.util.context.ReentrantThreadLocalBasedCodeContext.runOutOfContext(ReentrantThreadLocalBasedCodeContext.java:90)
at com.atlassian.servicedesk.internal.utils.context.CustomerContextServiceImpl.runOutOfCustomerContext(CustomerContextServiceImpl.java:47)
at com.atlassian.servicedesk.internal.web.CustomerContextSettingFilter.outOfCustomerContext(CustomerContextSettingFilter.java:174)
at com.atlassian.servicedesk.internal.web.CustomerContextSettingFilter.doFilterImpl(CustomerContextSettingFilter.java:130)
at com.atlassian.servicedesk.internal.web.CustomerContextSettingFilter.doFilter(CustomerContextSettingFilter.java:121)
... 4 filtered
at com.atlassian.jwt.internal.servlet.JwtAuthFilter.doFilter(JwtAuthFilter.java:32)
... 8 filtered
at com.atlassian.web.servlet.plugin.request.RedirectInterceptingFilter.doFilter(RedirectInterceptingFilter.java:21)
... 4 filtered
at com.atlassian.web.servlet.plugin.LocationCleanerFilter.doFilter(LocationCleanerFilter.java:36)
... 26 filtered
at com.atlassian.jira.servermetrics.MetricsCollectorFilter.doFilter(MetricsCollectorFilter.java:25)
... 24 filtered
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)