System information:

64 bit FireFox 65.0.2, Windows 10.0.17763

Repro steps:

1. Create a character sheet.

2. Go to Creatures tab.

3. Click Manage Creatures.

4. Set type dropdown to Summoned.

5. Begin typing mummy into the search bar.

6. Typing the letter "u" causes the page to crash.  See attached spew.

 Errata: this behavior appears specific to typing the combination "mu" into the search bar.

Error spew from page:

t/r.renderMetaDescription/<@https://www.dndbeyond.com/Content/1-0-82-0/React/CharacterTools/dist/characterSheet.bundle.min.js:57:430677 t/r.renderMetaDescription@https://www.dndbeyond.com/Content/1-0-82-0/React/CharacterTools/dist/characterSheet.bundle.min.js:57:430655 value@https://www.dndbeyond.com/Content/1-0-82-0/React/CharacterTools/dist/characterSheet.bundle.min.js:57:430982 f@https://www.dndbeyond.com/Content/1-0-82-0/React/CharacterTools/dist/characterSheet.bundle.min.js:31:33619 beginWork@https://www.dndbeyond.com/Content/1-0-82-0/React/CharacterTools/dist/characterSheet.bundle.min.js:31:37062 o@https://www.dndbeyond.com/Content/1-0-82-0/React/CharacterTools/dist/characterSheet.bundle.min.js:31:53322 i@https://www.dndbeyond.com/Content/1-0-82-0/React/CharacterTools/dist/characterSheet.bundle.min.js:31:53595 b@https://www.dndbeyond.com/Content/1-0-82-0/React/CharacterTools/dist/characterSheet.bundle.min.js:31:56544 g@https://www.dndbeyond.com/Content/1-0-82-0/React/CharacterTools/dist/characterSheet.bundle.min.js:31:56084 flushInteractiveUpdates@https://www.dndbeyond.com/Content/1-0-82-0/React/CharacterTools/dist/characterSheet.bundle.min.js:31:59776 X@https://www.dndbeyond.com/Content/1-0-82-0/React/CharacterTools/dist/characterSheet.bundle.min.js:31:9375 Ge@https://www.dndbeyond.com/Content/1-0-82-0/React/CharacterTools/dist/characterSheet.bundle.min.js:31:17354 interactiveUpdates@https://www.dndbeyond.com/Content/1-0-82-0/React/CharacterTools/dist/characterSheet.bundle.min.js:31:59690 Ye@https://www.dndbeyond.com/Content/1-0-82-0/React/CharacterTools/dist/characterSheet.bundle.min.js:31:17099

Component stack trace

in t in t in div in div in div in div in div in t in div in t in Connect(t) in div in div in div in div in t in Connect(t) in div in t in Connect(t) in div in div in t in Connect(t) in t in n

Wow. Can confirm, typing "mu" into the manage monsters search bar under any category crashes page immediately.

What a bizarre bug.

Further information: Version 1 character sheets from D&D Beyond launch do not appear to exhibit this bug.

If you copy "mum" as text and paste it in the box, it doesn't crash.  If you then delete the last "m" it crashes. 

That is weirdly specific. 

Had to see for myself. Indeed it does. Mac OS 10.14.3 Safari 12.0.3

This appears to be fixed as of 3/10/19.