DiscordSRV: 1.18.1
Server: PaperMC 1.14.4 (Build 225)

Discord debug:
https://bin.scarsz.me/ef460ac9-6d82-4f71-be9b-7481c8c2dbb3#F1Il15HT3W8aqX43enMQJ18XZORzLvDh

Other notes:
The topic is under the max character limit Discord gives (888 characters remaining) and the bot has permissions to manage the channel and therefore the channel topic.
The topic did update before version 1.18.1

Please set DebugLevel to 1, run /discordsrv reload, wait until the topic updater goes through a cycle (~5 minutes (as per configuration)) & make a new debug report

Here's the new debug with your requested changes
https://bin.scarsz.me/73588ede-318b-43cc-88ad-3843daa0be52#7H0ao670RDcHcPlDL2cTI5XPrqYbi8Xk

Hopefully fixed with 2cb358a

I'm able to reproduce this, no clue why, might be something within JDA

I assume the latest dev build would contain this change to test it?
If that's the case then I would appreciate if you could provide a link as the CI link on the resource page returns a 522 error.

https://lol.scarsz.me/ngRgEA/DiscordSRV-Build-1.18.2-SNAPSHOT.jar

I added latest release and now have this error on startup:

[03:17:51 WARN]: Exception in thread "DiscordSRV - Channel Topic Updater" java.lang.NullPointerException
[03:17:51 WARN]:        at github.scarsz.discordsrv.objects.threads.ChannelTopicUpdater.applyPlaceholders(ChannelTopicUpdater.java:75)
[03:17:51 WARN]:        at github.scarsz.discordsrv.objects.threads.ChannelTopicUpdater.run(ChannelTopicUpdater.java:45)

Also, this message is send too:

[03:17:51 WARN]: [io.sentry.dsn.Dsn] *** Couldn't find a suitable DSN, Sentry operations will do nothing! See documentation: https://docs.sentry.io/clients/java/ ***
[03:17:51 WARN]: [io.sentry.DefaultSentryClientFactory] No 'stacktrace.app.packages' was configured, this option is highly recommended as it affects stacktrace grouping and display on Sentry. See documentation: https://docs.sentry.io/clients/java/config/#in-application-stack-frames

First error should be fixed with 8b3f84b, https://lol.scarsz.me/cJToWw/DiscordSRV-Build-1.18.3-SNAPSHOT.jar

As for the second... I don't think that's related to DiscordSRV. Sentry isn't depended on by any of DiscordSRV's dependencies and those packages don't exist in the jar.

The error is fixed.
Also, I thought it could (at least) be related to DiscordSRV, since the error does no longer appear after the topic updater was fixed.

Perhaps an internal dependency could be using it? Just a guess.

The topic updater being fixed surely has nothing to do with Sentry. There are no internal dependencies to Sentry, as I mentioned.

I found this smaller warning when stopping the server:
[12:17:46 ERROR]: [DiscordSRV] Broke from Channel Topic Updater thread: sleep interrupted

That is to be expected; Java interrupts all threads when the JVM shuts down